Torchwood/WMG

For examples from Miracle Day, see here.

The very strange man who runs Torchwood 2 is Balamory's Archie the Inventor
Pure Crack, but totally true in my opinion.

Captain Jack's real name is Dark Blue
Because  name is Gray and he wears gray clothes. And since Jack wears Dark Blue clothes...

The very strange man who runs Torchwood 2 is really Bracewell
No real evidence for this, other than Torchwood 2 is in Scotland and Bracewell had a Scotish Accent and would be considered Very Strange to most people.

Jack is Jesus.
His initials (including the Captain part) are CJH. A common expression is Jesus H. Christ. JHC - CJH.

The creatures that attacked Jack's childhood homeworld were Time Lords.
In the show the attackers are never named or showed. It can't be the Daleks due to them only exterminating, not kidnapping and torturing. It can't be the Cybermen for a variety of reasons. They could give the creatures a name but they never do. It was implied/mentioned that the Time Lords had become just as bad as the Daleks so it could be imagined that they would be capable of the various acts of cruelty the attackers are known for.

Jack called Captain John Hart to pick him up at the end of Children of Earth.
It goes with the whole grieving, angsty (ineffective) self-destructive behavior when Walking the Earth just isn't enough of an escape.
 * The ship he described that he was getting a ride from sounded like the one John was offering earlier..
 * Or he could be recruiting the surviving time agents and mercenaries to go find where the 4-5-6 live and blow it all to hell. That would be awesome!
 * Going batshit crazy and trying to completely destroy all the 456 - that's more or less what he should have done at the end of Children of Earth. Instead,.
 * No, Jack,

Frobisher's wife and daughters
...via (FILL IN THE BLANK)! Why not?
 * It's not impossible.
 * Perhaps
 * A pony.
 * He's such a bad shot it took four shots to finally hit himself.

Steven
...via (fill in the blank). Same deal as below.
 * Steven Moffat . RTD ?.
 * His mum . Don't ask how she would get it—that's not important.
 * Jack has Haruhi powers and will use them. See theory at the bottom of the page.
 * Jack has Haruhi powers and will use them. See theory at the bottom of the page.

Ianto
...via (fill-in-the-blank). There's a lot of theories floating around, so let's just drop all the simpler ones here:
 * Jack's kiss.
 * Jack having Haruhi powers.
 * Chris Chibnall writing the next season and either not being aware or just pretending it didn't happen. Or coming up with some unlikely reason.
 * Chris Chibnall isn't writing for or producing series 4.
 * The 4-5-6 . RTD just messed up the ending. Or Jack
 * The 4-5-6 . RTD just messed up the ending. Or Jack

Ianto
Just a guess
 * Depending on your definition of "back", . Plus, technically John Fay killed him.
 * Depending on your definition of "back", . Plus, technically John Fay killed him.

Children of Earth happened because Drosselmeyer gained control of Britain and decided to write a grand tragedy.
Or, Drosselmeyer has had control over Britain, or at least Cardiff, for a while. Ianto had been keeping him at bay via that diary of his. The other characters were not aware they were in a tragedy and so were not trying to prevent the story from progressing. When, everything went to shit because they no longer had.

Ianto is via Rift time/space radiation.
In the episode "Reset," the creepy doctor states that Martha's white blood cells have mutated due to time-travelling radiation (or something). That was a Chekhov's Gun. . THAT EPISODE WAS NAMED "RESET" FOR A REASON.
 * What reason? It's named after the drug that had the eggs of the creature inside Martha the doctor was testing on her (which "reset" the body of diseases, but that's the reset itself, not any time radiation).

Ianto via Stable Time Loop!
He never. He isn't. So what happened?

Well, his

Ianto
Because I won't let it happen.
 * Alternatively, Ianto is.
 * Parallel universe! Say it with me!
 * Parallel universe! Say it with me!

The 456 aren't as tough as they seem.
They're using fancy gypsy tricks to make the children speak in unison and give a few people the appearance of death, but other than that they're useless. They haven't shown that they can do anything else. COBRA explained in "Day Four" that their satellites could not detect any ships in orbit - they're not beyond our technology, they just don't have any ships. They're taking over Earth with nothing but fear. Also links to the below theory.
 * I was thinking that too. Maybe none of the victims who
 * "Pay no attention to the crab behind the curtain."
 * A related proposal: There was only ever one member of the 456 - the one we saw. That's why there are no ships in orbit - the only 456 has descended to Earth already. ...However, it seems to only need one child at a time; what does it do with the other millions?
 * He is not the only addict among his species, he wanted to sell them to the other addicts.
 * It's definitely worth noting that the 456 invasion was broadly similar to the Sycorax approach. And while the Sycorax were formidable in their own way, the blood control angle was just 'a cheap bit of voodoo' and in the end Torchwood (albeit a slightly more effectual one) proved capable of blowing them out of the sky.

Captain John Hart is Spike.
Spike is immortal, and a vampire, which explains his appearance in Jack's time and his omnisexuality. He's also got a soul, hence why he turns out to be good while still being a dick (and not biting everyone).
 * There's a complimentary theory over on the Angel WMG that Jack is The Immortal.
 * If Captain Hart is Spike, than either he got the Shanshu and then had his aging stopped like Liz 10, or there are still some vampires under Extra Strong self-repaired Masquerade making mojo by that time, because he can be seen entering Torchwood through the guest door in broad daylight.

Rhys Williams is already a member of Torchwood and plays dumb to throw suspicion away from himself.
Or he secretly works for UNIT, or ICIS... or the SGC... or the Watchers Council.
 * Nah, Rhys is quite clearly The Master. His knowledge of the future would let him know to hook up with Gwen before she joined Torchwood. His mesmeric abilities would also explain how he managed to hook up with Gwen, given that everyone acknowledges she's out of his league. It isn't yet known what long game he's playing...

Owen is
We never saw, and in interviews, the actor who plays him has been evasive and even hinted at this.
 * And he didn't
 * He might eventually
 * Given his physical condition

At some point, UNIT and Torchwood are gonna fight each other.
With a handful of troubled individuals and a corrupt military organization coexisting, something will go wrong.
 * And it will be AWESOME!

Torchwood employs (or enslaves) a Timelord.
Torchwood 1 was Canary Wharf; Torchwood 3 is Cardiff. Torchwood 2 is "a strange man" (this coming from Jack of all people) in Glasgow. Possibly it is Salyavin, a renegade Time Lord that was supposed to be in the Doctor Who serial "Shada", which was never aired but considered by most to be in continuity. Maybe he had to drop his old job as an Cambridge professor (a job he had been in for ages, people just don't ask) and is waiting for his time to make his move.
 * It's the Seventh Doctor, who on the surface appears to be a strange little Scottish man, and he's manipulating everything that's happened in modern day earth - and possibly elsewhere, you never know with Seven; maybe he's orchestrating the entire Time War from behind a desk in Glasgow - in both the new series and Torchwood via a huge Xanatos Roulette. He then wiped his memory before collecting the Master from Skaro so he would react naturally and avoid having his knowledge of his Xanatos Roulette make him a Spanner in the Works.
 * It's the Valeyard, and not just because he's on the verge of becoming a meme. It's probable that the Doctor can't sense the Valeyard in his head because he didn't sense himself in 'Time Crash' (and really, sensing oneself throughout time and space when you've got a time machine would drive you bonkers) or he's actively ignoring his darker side. Also, it's time our favourite verbose prosecutor used a taunt based on the Doctor's name for once, and the only good one I can think of is Cock-Blocktor. Hello, watershed.
 * I'm pretty sure that one of the (admittedly non-canon?) novels implied that Bilis Manger was 'Archie', the strange old man of Torchwood Two.

The Tarot Card Girl is
It would explain why she's. As to why she hasn't aged, that probably
 * You mean that isn't canon?
 * I hope that is canon, because that's good Fridge Logic...

The Tarot Card Girl is from an alien species that lives a very long time
It would also explain how she's around after 100 years and why she hasn't aged.

The nuclear power plant in "Exit Wounds" is the end result of the Blaidd Drwg project in "Boom Town".
In the Doctor Who episode "Boom Town," the Slitheen-known-as- intends to build an extremely faulty nuclear power plant in the middle of Cardiff, with the intent of blowing the Earth to bits. Sure, the Doctor takes care of the Slitheen, but the industrious citizens of Cardiff finished the nuclear plant anyway, which explains why a city like Cardiff has one. It also explains why the power plant had so many ridiculous failures over the course of "Exit Wounds" (it was extremely faulty) and why it could apparently be shut down by the internet.
 * One of its biggest faults is the fact that you can apparently route radioactive coolant into the control room! Nobody in their right mind would design something that malevolent unless they were planning to kill everybody in the control room.
 * And surf off on an interstellar surfboard using the plant in tandem with the Rift to destroy Earth. It's PERFECT.

Series Three will have two new main cast members.
Okay, so it's really mild guessing, but the team needs a medic and someone with the tech skills of Tosh. (Though Ianto was becoming Smart Guy-ish in series two.)
 * This seems like it could be true, as
 * The most recent press releases indicate that there will be no new team members whatsoever. Not even . Rhys and PC Andy may take on similar roles, though.
 * The press release says one thing, but still... Doesn't it seem odd that they kill of their doctor AND their tech person, and yet, the two Jack walks away with are a doctor and a tech guy respectively. Curious, that.
 * Rhys is taking on a role as an unofficial member in season 3.
 * It appears that they indeed intended to have and  join the Torchwood cast for the miniseries, but neither actor could appear due to scheduling conflicts.
 * Martha is explained to be on her honeymoon and still working for UNIT. No sign of Mickey though.
 * Mickey's absence is accounted for in !
 * Jossed. Rhys is promoted to "main character", but no-one else particularly qualifies. Also, no-one really fills in for Tosh, though Esther in Miracle Day might fit.

Torchwoods Five and above exist, and are located in Commonwealth countries/former members of the Empire.
Torchwood's original brief was to protect the British Empire from alien destruction. It would make sense, therefore, for there to be Empire outposts of Torchwood, and for those to exist in some form today. Ottawa has a history of strange things happening, so a Torchwood branch in Canada's capital would make sense. Torchwoods in Sydney, Hong Kong, Delhi, and Cape Town have also been proposed and rationalized; the mission that  sent Torchwood Three on in "Last of the Time Lords" would be supporting Torchwood Delhi's operations.
 * Torchwood 42 will be centered on the planet Corneria, disguised as a Mercenary outfit.
 * The Torchwood audio episode "Golden Age" comfirms that they had a base in India.
 * Though it also states it ceased functions in 1924, losing all but one of its alien tech. Jack didn't even know about the Duchess and other people there until he investigated the disappearances in Delhi.
 * There is a Torchwood in the USA, which the Americans took over sometime during the Revolutionary War. It was renamed Area 51, and will be revealed in Season 4.
 * Revolutionary war - 1775–1783. Torchwood Founded 1879.
 * Overall Jossed. Miracle Day states several times that as of 2011, all that remains of Torchwood is Jack and Gwen. Also, Area 51 has already appeared twice in Doctor Who, so unless the team travel back to the Revolutionary War to when this was apparently still functioning as a Torchwood base (despite Torchwood being founded in 1879), such a reveal wouldn't mean much.

The single member of Torchwood Two in Glasgow is named McCrimmon, and the position is passed down in the family.
After Torchwood was formed, investigations found records that implied an appearance by the Doctor during the Battle of Culloden in 1745, witnessed by Jamie McCrimmon. Torchwood found that the McCrimmon family had been keeping this knowledge of aliens a secret for a century and a half, and offered a young member of the family a position working with them. That position has been handed down from father to son to the present. According to established continuity, Jamie did remember his first encounter with the Doctor, and probably recorded it or had someone record it for him.

Note that this would not invalidate the Season 6B theories; Jamie could have returned and sired a family at any point, and it makes it easier from the family knowledge standpoint if Season 6B had happened.
 * Perhaps they intentionally tracked down anyone with that name after The Doctor uses it when introducing himself to the queen.

Torchwood Three is not the only renegade splinter group of the Institute. Maybe not even the first.
This could be why Torchwood Four is 'missing'.
 * Jack is on speaking terms with the 'strange man' at Torchwood Two; compare with how he treats Ianto when he's unemployed after the battle of Canary Wharf.

Jack only ages went he doesn't die for an extended period of time
When Jack is  at the end of season 2, he is   looking exactly the same, despite the fact that The Doctor and the begining of Torchwood. This is because he dies at a much slower rate: aproximately 10 deaths a year, giving his body time to age properly (if slowly), rather than the hundreds of thousands (or, at the very least, tens of thousands) of times he dies while under Cardiff.

Jack is a descendant of the Petrelli Family
See, when Rose brought Jack back, she didn't bring him back wrong; she only activated the long dormant "special" gene. And Heroes does have canonical immortals.

Jack is a Captain Ersatz of James Kirk
He's a captain from a future where humanity's mission is to find new alien life and have sex with them. Furthermore, the series makes a big deal about how he's supposedly American, despite him coming from a century and a planet in which America isn't around.
 * Him being described as an American by British characters is just from his accent, accents are pretty coincidental in the Whoniverse - "Lots of planets have a North!"
 * I'm sure he confirmed himself that at the very least, his accent is derived from Americans, even if the Boeshane Peninsula is off-world.

Torchwood Four is the Forge in the Big Finish audios.
It "disappeared" because Nimrod took it over and cut off ties with Torchwood One.

Torchwood and the current run on Doctor Who DO NOT take part in the same universe.
Simply because the Jack of Torchwood does not appear to be the Jack from Doctor Who. Any other coincidences are there due to the fact that the universes are similar. This could also mean that the idea above about the 'strange man' in Scotland was and still is this universe's version of the Doctor.
 * This explains why at the end of "Captain Jack Harkness" the TARDIS lands inside the hub (evidenced by all the paper and Jack's hair being blown about) while in Doctor Who's "Utopia" it lands above it. This also explains why Jack didn't see his team again until night in Torchwood when he came back in "Kiss Kiss, Bang Bang", the Doctor dropped him off later than he did in Doctor Who's "Last of the Time Lords" (morning).
 * Possibly jossed. Word of God mused that after "The Big Bang" the rift in Cardiff either was or likely sealed as well. Possible, admitted, rebuttal to my rebuttal, The Alliance seem to believe the effect could be multiversal. In either case, RTD considers Torchwood post Series 5 Doctor Who to be in a universe following an event much like "The Big Bang", if not THE BB occurring.
 * While I can't explain the continuity errors about morning/night, or the stuff blowing around, it still seems evidently Jossed in series 2. Jack meets the time traveller Martha Jones in "Reset", and though he doesn't say the words "Doctor" (with a capital D), "TARDIS", "Yana", "Harold Saxon" or "Master" he muses in that episode about having a bad experience with a politician, references orders from above promoting Martha in UNIT, and states that he and Martha are part of an "end of the world survivors club". The flashbacks in "Adam" mention Jack's childhood on the Boeshane Peninsula, which echoes the fact that in Doctor Who's "Last of the Time Lords", Jack was the Time Agency poster boy from the peninsula. Also Jossed in Doctor Who series 4, where Gwen and Ianto appear with the Torchwood hub clearly visible in the background (and they died in the Turn Left universe saving the world from the Sontarans. Sontar-HA!). Jack even paraphrases the "on a cold night in Wales I hear the voice of a nightingale" speech in the Doctor Who series 4 finale. Furthermore, there's the newspaper article from "Boom Town" ("New Mayor, New Cardiff") on one of Torchwood Three's doors at some point in Torchwood series 2.
 * And was that a direct reference to the Doctor, travelling the world, his companions AND the Trickster's Brigade I saw in Miracle Day?
 * And in a later episode, Silurians and Racnoss. Apparently UNIT, too.

The first order Jack gave Owen after recruiting him was to
Think about it. The other two people that we know were in Torchwood at the time were Suzie Costello and Toshiko Sato, neither of which have anything remotely resembling experience in the subject of biology (since Suzie did weapons and Tosh did technology, as far as we know). And in "Day One", Toshiko reveals that Owen cried on his first day, which would be explained by the fact that he had to. There could be an extra level to this - Owen could've insisted on doing it himself, affected by grief and not wanting to let anyone else dissect his beloved.

Torchwood 2 is run by an ex-Time Agent.
As noted above, Jack called the person who runs Torchwood 2 "a very strange man," and Captain John told Jack that the Time Agency had been disbanded (then again, Captain John is a liar, but he didn't seem to be lying about that). Since the Time Agency was disbanded after Jack left, it's possible that another Time Agent—probably one that Jack wasn't familiar with—came across Earth and ended up running Torchwood 2.

Rose didn't make Jack immortal, she gave him Haruhi Suzumiya powers.
He does seem to often get exactly what he wishes for, after all. He is immortal because he wanted to be. He wanted an excuse to find The Doctor (aside from just being pissed about the abandonment situation), and possibly has an unconscious fear of dying before he's done everything he wants to do. He doesn't really want to live forever or even stay young forever which is why he is aging (albeit slowly). This would also explain some Torchwood events: I could go on and on, but I'll leave it as this for now.
 * In Cyberwoman he wanted to rescue his receptionist, but he didn't know how to use CPR. So he wished that snogging could heal people.
 * Directly before he and Tosh were sucked into the past near the end of the first season, Jack was reminiscing about the good ol' days when soldiers danced with cute girls before going off to war. When they returned to the spot where Jack had been reminiscing, it was exactly what he wanted it to be: soldiers and music and girls and dancing. He also probably wished to meet a cute guy who was crazy about him. Maybe he even wished to meet the man who's name he stole!
 * At the end of Season 1, he really wanted Gwen to kiss him again, so he subconsciously made himself dead until kissed. After his Gwen-kiss fix, he snogged another employee for good measure, then decided that it was the natural time to ditch his friends, and wished to see The Doctor again.
 * The only reason the episode Adam happened was because he wanted to read Ianto's diary.
 * In From Out Of The Rain, Jack was ticked that Gwen, Teaboy, and Owen went to the cinema without him. So he subconsciously wished something bad would happen.
 * In Adrift, Jack secretly wanted Gwen to find out about the rift victims, he just wished she would find out for herself.
 * At the end of season 2 Jack wished to see Gray again, and he got his wish.
 * He wanted  Or at least, didn't want to bring him back from the dead?
 * Well, I think this is effectively Jossed at this point.
 * Or he subconsciously wanted to  and the power acted on those
 * Jossed on the "excuse to find the Doctor" count, according to both Doctor Who and Torchwood itself. Jack wanted to go to 21st century Earth to reunite with the Doctor when he parks again at the Rift. Landing in 1869 (when he likely doesn't even know about the adventures with Gwyneth and Charles Dickens) makes absolutely no sense.

The post of Prime Minister is like Defense Against the Dark Arts teacher or Spinal Tap's drummer in the Whoniverse
...and seeing the events of Children of Earth it seems things would almost have been better off if the Master was still prime minister...
 * Or Harriet Jones, former Prime Minister. She would have blasted their asses to hell and back. Nice Job Breaking It, Doctor!
 * She probably did, in Pete's World.
 * Can you imagine if the PM in that story was Harry Saxon? Or at the very least Harry was on the Cabinet at the time? That could explain why there's no Doctor (because really - this is EXACTLY the sort of crap that gets his (or the TARDIS') attention). I can imagine him sneaking into floor 13 as the Pink Panther theme is played over the PA.

The Doctor was of fighting an even greater threat during Children Of Earth
He was trying to prevent a catastrophe of galactic proportions, agonizing over his inability to intervene in Earth's situation, he was not tut tut tuting about how giving your children to be used as drugs for all eternity is bad, he would be helping if he could.
 * I'd like to think so too, but there's a problem: he could just come back in time when he's done. The Doctor can be in lots of places at the same time as long as he doesn't cross his own path (and sometimes he even breaks that rule). There's another possibility, though...
 * I personally like to think that while Torchwood was dealing with the emissary and fleet, The Doctor was on their homeworld addressing the root of the problem.
 * When does Children Of Earth take place? I think we could probably reconcile this with an event which stopped the Doctor from showing up.
 * A newspaper article sets it in September 2009. Though that said, Torchwood's own dating can be pretty irreconcilable, as "Greeks Bearing Gifts" is hinted to be set that year.

Jack Harkness is
Some very, very subtle hints of this were dropped throughout the series.
 * I thought he was.
 * That's too bizarre. Even for WMG.

The Doctor can't go back and stop the 456 because the events of "Children of Earth" are fixed in time for him.
If someone had contacted him during the 456 crisis, he could have helped out. But no one did—which means the Doctor will first hear about the incident from someone who's already lived through it. And as soon as he does, it's part of the past for him too, and he can't change it.
 * Maybe CoE was meant to be in the Doctor's future, but something went wrong as a consequence of him breaking the rules and changing something else, something trivial, even. Alternatively, there was an unseen Big Bad behind the 456 who had already immobilised the Doctor somehow. Said Big Bad could also have told the Doctor what they were doing while he was powerless to stop it because they were playing God to show how horrible humans can be when they're cornered. Tropers and editors, I give you Space Joker.
 * Who says it has to be Space Joker? If an alien race were to create a device that can make fictional characters real (and it's likely one would), someone could just use it to bring Joker into reality. He kills his "creator" and steals a ship. He overpowers 10 or 11 and makes him watch.
 * Such a device does exist, in the Second Doctor serial "The Mind Robber." However, it seems to be outside the universe, which would make it hard to get one's hands on.
 * I confess I'm not well versed in Doctor Who, but I did see Blink. Didn't the doctor learn about the events of Blink after the fact when Sally gave him the info?
 * Yes - including, presumably, information about his own involvement. He knew he needed to record his half of the conversation and make sure it got onto the DVDs because of the information Sally gave him; from her point of view, he was always involved. (Also, that was the episode that gave us the "wibbly-wobbly timey-wimey" explanation of time; the rules of time are complex and it's implied that the Doctor himself doesn't fully understand what is and isn't possible.)
 * The funny thing about "timey-wimey" being introduced in this episode is that it isn't timey-wimey at all. It's a stable time loop. This troper thinks they all boil down to Stable Time Loops in the end. Back to the topic: since they're all Stable Time Loops, and the Doctor wasn't there, he can't be there.

The accent most Time agents have sounds to our 21st century ears like a cross between British and American
Jack and Captain John Hart's American with Britishism and British with Americanism accents are common in the Fifty first century.

Captain Jack Harkness is the son of Robert A. Heinlein's Lazarus Long and/or The Time Agency is the organization run by Lazarus Long.
I'm surprised no one mentioned this before. Both are quasi/near immortal. Both are very open to 'dancing'. Both feel very strongly about protecting people they care about. Both are good at hiding weapons (In The Number of the Beast and in the Dr. Who episode Bad Wolf, each character was stripped naked and still had a hold out weapon). Both tend to lie about their own past.

Torchwood Four is a robot or a non-humanoid alien.
"Torchwood Four has kinda gone missing but we'll find it one day." Not him, her, or them, but it. So it's something without gender, like a swarm of bees, a really weird alien or a friendly Cyberman.
 * The name "Torchwood Four" probably refers to the facility itself and the (probably) non-zero number of people who work there collectively, as such "it" is perfectly appropriate.

are the people behind the 456.
The whole thing was an elaborate Evil Plan to kill off and therefore eliminate all their competition  The monster is a deformed clone of their mascot.
 * And has a shop just above Torchwood, a stone's throw away from the 'Tourist Information Center' entrance.

Jack's memories were erased because he saw his future.
He had been working on a two year mission and accidentally stumbled on something that told him that he would one day become immortal. The Time Agency were worried he'd Go Mad from the Revelation so they Retconned him and all memories he had of that mission in case they triggered a recall. The Doctor (11 or 12)probably got in touch at some point to tell the time agency just how important that Jack does what he's supposed to.

Torchwood 4 was vanished by a negative rift spike
It hasn't returned them I Hope...

The rift spike dropped Jonah in the Time War
And the man who pulled him out of the fire was the Doctor. Because it's a cool idea.
 * I have to agree, but it would have to be Nine
 * I was going to say the same thing. Though I think it would have to be 8 since 9 seemed to have not seen himself before he met Rose.

One of the new characters in Children of Earth will join Torchwood
Lois is an obvious one, but I'd love to see Johnson. The jokes they could get about how she blew up the old base...
 * With everything Jack and Gwen lost in those five days, I very much doubt they'd feel like joking about it. Or thinking about it. Or, unfortunately, having Johnson around at all.
 * Jossed. Besides, Torchwood effectively ceased to exist (though the name was revived with Miracle Day, but that was still two years afterwards).

Owen is a Death Knight
Death Knights are former members of sentient species raised into undead by a powerful being which has domination over (un)death. They run on unholy energies which they replenish by slaying foes. They usually only show minor signs of undead (the most obvious are iceblue glowing eyes) und retain much of thier free will and memory. Lets see what applys to Owen: For me it is enough to hand him a freaking runeblade.
 * 1. raised as undead by powerful being with domination over death... check
 * 2. shows only minor sign of undead... check
 * 3. retains his free will and memory... check
 * 4. will die sooner or later when unholy energy fades... check
 * He hasn't come back yet because it's a long run from the Cardiff Zone graveyard to his body. Or maybe the radiation is corpse camping him.
 * I thought Jack raised him, and Owen was just a sort of vessel for "Dead Man Walking"'s powerful being. Do you know something most of us don't?

The Time Agency is the Torchwood of the future
I don't have any real evidence for this, other than the Stable Time Loop of Jack heading Torchwood could bring about Vortex Manipulators and he'd be in that time period as well as this one. Interesting thought, though.
 * Perhaps that's where Starship UK from "The Beast Below" went.

The Face Of Boe is Jack...
The Face Of Boe could be what happens to Jack if his cells aren't forced to regenerate for a long time. He may well have just got up and walked away after The Doctor left.
 * But then wouldn't he come back to life looking like Boe? I mean, it's just his head, where's the rest of him?

Weevils stole the Torchwood van from Ianto
And, lacking their own spaceships, used it to drive to Stonehenge to be present for the opening of the Pandorica.
 * So they drove back in time then?
 * Well, if a Delorean could manage it, then surely an SUV souped-up with alien technology can pull it off....
 * Didn't we clearly see humans (or at least a human backside) inside the van?

Jack specifically recruited his Season 1 team to juggle the Idiot Ball
Everyone on the team, from Suzie through Gwen, is hypertalented but hyperdisfunctional. In Season 1, this is deliberate—After waiting centuries for the Doctor to get him, Jack specifically planned for his team to get in to the middle of (or create) a situation that would attract the Doctor's attention. After Season 1, of course, they're Nakama.

The original Captain Jack Harkness committed suicide by Nazi
Sure, the original Captain thought that our Captain was worth coming out for. But then our Captain walks into a rift, leaving the original Captain dumped and outed, in front of his command in the 40s. The next morning, the original dies heroically. Coincidence? I think not. Of course, a bit later, our Captain drops by and takes over the name.
 * But notice the looks on everyone's faces as the couple dance. No one seems disgusted, in fact, most of them have an, "aw, how cute" look on their face. God knows why considering the time period, but hey, maybe they're all just particularly nice people.
 * They looked more confused to me.

The Doctor Didn't know about the 456 until it was to late
There is no way the Doctor would let children suffer even if he was ashamed of what humans were about to do, and he has missed things before i.e. Army of Ghosts, also through his knowledge Harriet Jones was suppose to be the prime minster before he "brought her down with just six words". From what we've seen from Harriet's actions from the end of The Christmas Invasion the 456 probably wouldn't have been negotiated with, and the whole event probably never would have happened or just have turned out a lot differently then it did.
 * The theory also causes a bit of Fridge Horror as this means the Doctor actually caused the events to happen


 * No they would still have negotiated, as they would not want to reveal they had negotiated in 1965

The burning planet in "Adrift" was Gallifrey
Jonah was taken by the Rift and taken to Gallifrey in the last days of the Time War, when Gallifrey burnt. He was driven insane by looking into something (the Untempered Schism)), and the man who rescued him was the Doctor.

Unintentionally, the Doctor is the cause of 456

 * Word of God has indicated that Frobisher may have some connection to the family that the Doctor saved from Pompeii, due to actor reuse. That connection could mean that the events of Children of Earth was a timey-wimey way of curing itself of a hiccup. After all, it wasn't until Frobisher killed himself and his family that a solution was found that spared the Earth. This also gives an explanation for why the Doctor didn't interfere - he stepped in and saved them once, and time would continue to cause these events until it wiped out the line that shouldn't have existed. As for why it took so long to catch up... Uh, I'm gonna go with Timey-Wimey Ball.

Captain Jack keeps up a correspondence with his past lovers by mail.
John Barrowman has stated on more than one occasion that Jack will sleep with "anything with a postcode", which raises the question of why a postcode would be an important factor? Obviously, it's because Jack likes to have contact information so he can write them letters. This hypothesis is supported by his comment way back in the Doctor Who episode "The Doctor Dances" where he reminisces that ""The last time I was sentenced to death...I woke up in bed with both of my executioners. Lovely couple, they stayed in touch! Can't say that about most executioners.""

which suggests that he has kept in touch with these former lovers in some form. It is also shown on Torchwood that he made an effort to reconnect with and stay in touch with Estelle after losing touch with her years before. This desire to keep in contact with people may contribute to Jack's acute distress at his inability to keep in touch with the Doctor.
 * Jossed in Miracle Day (at least with people outside Cardiff). He starts a new life every time he ends relationships with past lovers, and never contacted Angelo.
 * Maybe not. Jack did come back for Angelo after Angelo was sentenced to prison. Jack left him afterwards due to the incident in the butcher shop. On the other hand, Jack kept in touch with that woman who loved fairies, even going as far as to convince her that he was his own son. He also mentioned to the Doctor that he saw Rose at various points, but never interfered due to timelines.
 * Jack didn't cut himself off from Angelo until after the butcher shop incident, so my last point still stands. Plus, seeing someone briefly is not the same as posting messages to Rose...which is kind of icky, given the content of the original WMG and when Jack briefly visited Rose.

Before learning he was the Master, Jack at some point had a one-night (or more) stand with Harold Saxon.
Evidence:
 * The Master would remember who Jack was, and want to have an inside scoop.
 * They could fairly easily have met, both being in government (more or less).
 * Simm!Master is definitely pretty enough for Jack.
 * The clincher: the way the Master says "handsome Jack" on the phone to the Doctor is very...knowing-in-a-kinky-way.
 * Is the Master trying to make the Doctor jealous, then? He obviously doesn't know Jack well at all.
 * Fridge Brilliance: No wonder the Master kept Jack tied up in the Valiant's basement!

Bilis Manger is the Happy Mask Salesman.
Bilis Manger; a creepy middle-aged Asian man with the inexplicable power to step through time and space at will, who also has ties with an ancient world-destroying demon. He's a salesman too, except he sells clocks instead of masks—but remember, the Happy Mask Salesman met with Link in Clock Town.
 * ...hold on, Asian?
 * Happy Mask Salesman's appearance was allegedly based on Shigeru Miyamoto so I assume he's meant to at least look Asian.
 * And Bilis?
 * Well... he looks Asian.

The Doctor will turn up in series 5/Torchwood will turn up in Doctor Who

 * Not strictly to do with the series, but if  from Miracle Day is  it would be the sort of thing to attract his attention.
 * I just want Jack back on Doctor Who. He was supposed to be in "A Good Man Goes to War."

Tosh
...via (fill in the blank). Rule of Cool.

Jack is actually conservative by 51st Century standards.
Remember, Jack was a small town boy. It's worth noting that despite being born in the sexually liberated 51st century, he hails from a traditional nuclear family (man, woman, two children). And unlike John Hart, he doesn't seem to be inclined towards beastiality or wanton murder (despite being rather trigger-happy) and vice.
 * That depends on your definition of bestiality. Strictly speaking, Jack will sleep with pretty-much anything sentient and consenting. In the Whoniverse that encompasses a whole wide variety of non-humans.
 * Well, he doesn't seem that interested in Earth animals (other than humans), in any case.

Jack was reluctant to hire Ianto because Ianto had previously worked with Torchwood 1
Jack hand-picked his team to consist of people that had not had previous contact with Torchwood, from Tosh (arrested by U.N.I.T. for espionage) to Owen (lost his girlfriend to an alien parasite). Chances were he preferred to introduce his own philosophy to dealing with aliens that had not been corrupted by the previous Torchwood's views of "if it's alien, we take it or destroy it!" Also he was probably not happy with the fact that Torchwood 1 indirectly caused Rose's "death" and the near-destruction of the world by letting in the Daleks and the Cybermen from another dimension.
 * It could also be Ianto's age. He was something like 24-25 in Season 1 of Torchwood and most of the other members Jack recruited were in their mid-30s at least!
 * Or it could have been a Secret Test of Character to check whether Ianto was serious about joining.

The creatures that attacked the Boeshane Peninsula were Reavers.
Sadistic marauders who descend on random worlds, capture people, and make one person watch while they torture the rest? Check. And while Jack is stated to be a native of the 51st century, by his era time travel is common, so his family could very well have migrated to the timezone that Firefly takes place in. This would also explain why the peninsula seems a bit primitive in comparison with what we've seen of 51st century tech.
 * Is civilian time travel ever said to be common in the Whoniverse? I always assumed it was just the agency and the alliance mentioned in Doctor Who's The Talons of Weng-Chiang.

Time itself is trying to wipe Jack Harkness out of existence.
As an "impossible thing", Jack is literally a living wound in Time. That's why he's met death so many times, and why death and tragedy seem to surround him wherever he goes: Time itself wants him gone. And the more lives that become intertwined with his own, the wider the path of destruction becomes....

The next series will see the return of
At this point Jack's continued Immortality and it now spreading to Rex means that the nature of these powers will soon be explored, and with this comes an ideal opportunity to re-explore the source of the phenomena.

Torchwood Four was located in Northern Ireland - more precisely, in Belfast.
Torchwood One was in London, Torchwood Three was in Cardiff, and Torchwood Two was in Glasgow - each the largest cities of their respective countries. It would make sense for Four to be in the largest city of the other UK country. In addition, Torchwood Five was located in Delhi - the largest city in India.
 * Following this pattern, Torchwood Six would be in Toronto.

Torchwood Four is a codename.
Torchwood Four is a catch all term for those not affiliated with the actual institute, but still dedicate their lives to protecting humans from supernatural threats. The ARC, SCP Foundation, Men in Black, The Winchesters, and even the Doctor himself are all classified as Torchwood Four agents.

Owen became King of the Weevils before .
At the end of Combat, Owen confronts one of the Weevils in the vault, and it's clearly frightened of him. We know that the Weevils are at least slightly telepathic, so it seems plausible enough that the Weevil he fought broadcast the news that a human fought him and lived. Fear evolves into a healthy respect, and suddenly Owen is the Weevil King.