Spoiled by the Format
It's a universal but occasionally unfortunate fact that any medium has some physical realization; often, facts about that physicality can allow you to figure out things about a work earlier than than the creators intend.
For example, when reading a book, you can tell exactly how much of it there is remaining. If you're near the end, you might realize that the end must come in a certain specific way as any other way would take too long to resolve. (Ending on a Cliff Hanger is one way to avoid this.) If you're not, you might know that the apparent resolution can't possibly last as there's too much book left.
Books also spoil through their page format, because a heavy reader tends to be able to read quickly enough that if they are concerned about, say, a character as they read down the left page their eyes can sometimes dart over to the right page to see what is being mentioned there. Some readers try to beat this phenomenon by placing a thick sheet of paper over the right page as they read a book for the first time, and are nearing the end of the book. E-readers avert this.
A similar phenomenon can happen for TV broadcasts due to their generally fixed length. For example, in a Dramatic Hour Long episode, any solution to a problem that comes after 20 minutes will generally fail, while any solution that takes 35 minutes will generally succeed. Even if your time sense is poor, you can often figure out whether the currently proposed solution is the correct one by counting commercial breaks. Similarly, mystery shows have a tendency to introduce the villain somewhere around the 15 minute mark: soon enough that they feel like an integral part of the episode, but late enough that they're not the first person you associate with the setup. Contractual Immortality and related tropes are another example of this in TV series: there is a clear delineation between "regular characters" and everyone else, which often spoils the suspense of whether any given character will die, get married, be promoted, etc.
A short-term variant of this can occur when watching TV shows and movies with closed captioning or subtitles, since they usually display a sentence before it's finished being said. This means that if a character's words are cut off in the middle of a sentence, you know that they're going to be interrupted by something a few seconds before it happens. In some cases, when it's obvious enough what the character is going to say next, it's possible to avoid this in subtitles by showing the whole sentence anyway, then making it quickly disappear when the character is interrupted. Some captioning includes the name of the person doing the speaking, which is especially frustrating if that person's actual identity is an important future plot point and hasn't actually been revealed yet.
Another variant of this is when the phrase "Part 1" is in the title- you know that it must end on a cliffhanger of some kind.
Contrast Your Princess Is in Another Castle.
- FLCL, being only six episodes long, evokes this feeling. They even Lampshade it with something along the lines of:
Haruko: What are you doing here? This is the climax! You need to be where the action is!"
- Lampshaded in an episode of Pokémon where, after several incredibly dumb attempts to steal Pokémon, Team Rocket actually tries something that might work. James wonders why they didn't start out with this plan, and Meowth replies that they needed to fill an episode.
- In Cardcaptor Sakura you can almost always tell when Sakura is going to miss the catch, simply because her attempt is actually animated instead of stock footage.
- Anime tends to come in rough multiples of 12- or 13-episode chunks. If you don't know going in that Death Note has an irregular number of episodes, this could be an issue.
- Lampshaded in an episode of Lucky Star, wherein Kagami and her family are watching an unnamed suspenseful reality game show and Tsukasa can't stand the suspense so she glances at the clock; with only a few minutes left in the hour-long program, she knows the person got a question wrong. Kagami, predictably, notices this and berates her for it.
- In Naruto Veangance Revelaitons, the author had a few estimates for how long the fic would run- as few as 30 chapters and as many as 10, with the most consistent estimate being 60 before settling on 69. As such, when Ronan dies in Chapter 12, 31 and 65, it's not hard to realize he'll come back before long; in the first case, he even comes back in the same chapter. Lampshaded by gubgub in her dramatic reading. In Chapter 70, however, all bets are off.
- An odd temporary example happened in the Katawa Shoujo fanfic "Rika Story", which sets out to imagine what a Rika route would be like, complete with Multiple Endings. The author wrote the bad endings first, so anyone who read it when they were the only options available would be able to figure out which choices were the wrong ones.
- Gone Baby Gone wraps up the plot neatly in less than an hour. You'll certainly be going "Wait, already?" when it happens. Yes, of course there's a twist.
- Unstoppable averts this, as shortly before the end, the train is coming back under control and it looks like everything's going to turn out fine. The brakes on the locomotive slowing the train down blow, and an Indy Ploy is required to get the runaway stopped before it escapes again.
- Famously averted in Psycho which led to Hitchcock requiring that audiences could only enter at the start of the film whereas up to that point it was the norm for people to come in while it was playing. Otherwise they wouldn't understand why the leading lady isn't in the film since she's murdered within the first half hour.
- In 1408, this is averted by having the room make Mike think he has escaped, very near the actual ending.
- According to the trailer, Savages goes out of it's way to avert this. The leading lady narrates, but early on, she says "just because I'm telling this story doesn't mean I'm alive at the end of it."
- U.S. poker-based shows that use the "all in" rule (a player bets all his chips) qualify. If there are two players left and a player goes "all in", the game will continue if and only if the player with less money wins the hand. So if there's only one minute left, the player with more money will win; otherwise, the player with more money will lose.
- Nicely averted in the latest main event on ESPN. They showed every hand the final pair played (with a 15 minute delay).
- The Japanese edition of Who Wants to Be a Millionaire? always have the current player's round ending by the end of the edition, something lampshaded by the aforementioned Lucky Star example.
- Cash Cab has a format in which players answer questions while taking a cab ride to their destination. If they get three strikes, they get kicked out of the cab. If it's getting very close to the end of the episode and they're nowhere near their destination, it's a pretty obvious sign they're going to lose and get kicked out.
- On The Amazing Race, it's a pretty sure sign that it's a "To be continued..." leg if it's just a few minutes until the end of the episode and still no teams whatsoever have checked into the Pit Stop.
The anxiety, which in this state of their attachment must be the portion of Henry and Catherine, and of all who loved either, as to its final event, can hardly extend, I fear, to the bosom of my readers, who will see in the tell-tale compression of the pages before them, that we are all hastening together to perfect felicity.
- The Tortoise and Achilles discuss this problem in one of the dialogues in Gödel, Escher, Bach by Douglas Hofstadter. They decide that books where this is a problem should have a variable amount of Padding at the end. Of course, if the padding consists of blank pages, or pages with some simple typographical pattern on them, anyone who casually flips ahead will know when the book is about to end, so you need the padding to actually look like a continuation of the book, but to be thematically different enough that a sufficiently assiduous reader can determine where the book actually ends. They also discuss other means of indicating the location of the "real" end, such as a hidden message or a rash of typographical errors; and sure enough, those are also used by the dialogue itself. Just when they've figured this out, two police officers show up to arrest the Tortoise for theft, and the dialogue ends. Of course, this is an ironic example because it occurs in a dialogue within a book. You can't tell from the weight of the book how much of the dialogue there is to go!
- Lampshaded twice in Bored of the Rings. Bromosel knows that he's going to die on the page 88.
Bromosel looked up to the top of the page and winced. "At least another chapter to go," he groaned.
"We cannot stay here," said Arrowroot.
"No," agreed Bromosel, looking across the gray surface of the page to the thick half of the book still in the reader's right hand. "We have a long way to go."
- Neal Stephenson's work just keeps going at the same pace until about 100 pages after you've finished reading the book, until you realize that you've actually read the ending in the last 50 pages or so. Cryptonomicon goes even further, having an ending before the end of the setup, before ending a subplot you weren't actually aware existed.
- Averted in books like The Lord of the Rings that have long appendices, as well as those that give a preview of the next book in the series.
- Averted in Hopscotch, which includes its own abridged version. If read from the first chapter to the last of the main story, in order, chapters 1 through 56 end with about half of the pages still unread. The remainder of the book consists of 99 expendable chapters, short appendices which can be read in between the chapters of the main story according to an alternate order; the first four chapters one reads of this extended version are those numbered 73 - 1 - 2 - 116.
- Deconstructed in David Lodge's Changing Places. The last chapter finishes with one of the characters talking about how he believes film is a superior medium to books because you can't tell when the story is about to end just by noticing how many pages are left. He laments the fact that the only way for a writer to avoid this would be to simply refuse to resolve the story at all. At that moment, the book abruptly ends, with its main conflict left unresolved. This is followed by several blank pages. Only after the blank pages does the book inform you that this is actually the first part of a trilogy. Thus it's a double subversion: The reader assumes there will be a resolution, both because of the low remaining page count, and because he doesn't know there are two sequels. Just to drive the whole movie point home, the last chapter is done in script format (the rest of the book is prose). The novel ends with the "film" burning up in the projector before the story can be resolved.
- House of Leaves is post-modern enough to avert this several times. There is a story within a story within a story, wildly erratic formatting (including some pages with just a word or two), footnotes that run for pages (not always left-to-right), several appendices, several appendices that are supposed to be there but are instead single-page notes about missing appendices, a short story tacked on the end, and a lengthy index. Come on, guess how many pages you have left.
- "You can't die in the middle of the fifth act" (from Peer Gynt — see below) is quoted by a Genre Savvy character in Jostein Gaarder's magnificently metafictional novel Sophie's World.
- Any Agatha Christie book, especially her Hercule Poirot ones. If you're 20 pages or so from the end and you have a pretty good idea who the culprit is, you are wrong.
- Averted in The Dresden Files book Changes. It certainly seems like everything's going to be okay, and Harry and Murphy will finally hook up, and then in literally the last two paragraphs, Harry is shot and killed.
- In The Princess Bride, when the sharks are circling around Buttercup, the narrator points out that "since the book's called The Princess Bride and since we're barely into it, obviously, the author's not about to make shark kibble out of his leading lady," though he was glad that his father told him that she doesn't get eaten at that point since he was a kid back then and not Genre Savvy enough to rule out the possibility.
- Mary Granpre's artwork for the beginning of each chapter of the American Harry Potter books was sometimes very spoiling. Some American readers tried hard not to look at the illustrations as they read for the first time.
- And unless you were reasonably expecting a 40-page epilogue, it was predictable Harry wouldn't die (or at least not stay dead) in the forest at the end of Deathly Hallows.
- However Rowling managed to avert this sometimes, she did a good job at padding pages so the big twists were at the top of the next turned page so you couldn't glance over at it as you read down the left-hand page. For instance the big reveal of Quirrell in the first book is right at the beginning of a chapter after a page turn. If the next chapter was on the opposite page, it would stand out like a sore thumb.
- Lampshaded in the Doctor Who Eighth Doctor Adventures novel The Infinity Doctors, in which the Doctor, captured by the villain on p229, happens to mention that if the hero's captured on p229 of a 280-page novel, he's clearly going to get out of it pretty quickly.
- Not a problem, one presumes, for one of the alien races mentioned in the Hitch Hikers Guide to The Galaxy series, whose books always consist of a set number of pages, with the story terminating, quite probably mid-sentence, at that point, even if the actual plot of the story was finished many, many pages earlier.
- The big reveal at the end of Ender's Game is spoiled by the fact that there are very few pages left in the book.
- Besides Bella's not-suicide cliff diving in New Moon (as evidenced below), there's also her birthing of Renesmee in Breaking Dawn. All of the tension as to whether or not she'll live falls rather flat when one considers that it happens at the end of part two, there's a buttload of pages left for part three, and that section is told from her point of view.
- Battle Royale tried to avert this. The author tried to make the readers believe Shinji Mimura and not Shuya Nanahara was the male lead. As such, his death in the middle of the book would come as a big surprise. This however failed due to the design of the cover that already hints who is the lead.
- Discussed,on the first page, in fact, of Charles Dickens' 'Oliver Twist:
It remained a matter of considerable doubt whether the child [Oliver] would survive to bear any name at all; in which case it is somewhat more than probable that these memoirs would never have appeared; or if they had, that being comprised within a couple of pages, they would have possessed the inestimable merit of being the most concise and faithful specimen of biography...
- Law and Order is built on a very consistent pattern: The first half is detective work, the second half is the prosecution, and the episode ends with the verdict. Some episodes avert this by having the criminal caught and convicted within the first 15 minutes. The audience knows that a stunning twist or a second crime is about to occur because the show violated its format.
- Episodes of CSI and its spinoffs tend to follow a general pattern - the bulk of the episode is spent following the clues of the case of the week, with the solution to said case coming within the last five minutes and the resolution of the B plot case (if there is a B plot) coming just before or after. As such, anyone designated as a prime suspect before fifty minutes  into the show is virtually guaranteed to be innocent. The format is often played with, however:
- The season 7 episode "Toe Tags" presents a series of short cases, punctuated by the corpses of the victims discussing their cases with each other.
- "The Unusual Suspect" in Season 6 deals with a brother and sister who have confessed to the same murder; the team must decide who is lying. Neither - and they both get away with it.
- "Turn, Turn, Turn" in which Taylor Swift guest starred as victim Haley Jones. The episode opens fairly normally, with Nick Stokes arriving at a crime scene to find Haley dead. From there, however, the episode travels backward in time to a number of previous cases at the same location, all of which have some bearing on the current one.
- "Ending Happy" turned this into a Running Gag: each time the characters thought they had nailed the suspect, they'd get a call from the morgue doctor explaining that whatever that suspect did wasn't the actual cause of death. See the episode's entry under Rasputinian Death for further details.
- "Chaos Theory", had a similar storyline: As the episode progressed, every possible suspect was eliminated by the CSI's own investigations. Somewhere around the 43 minute mark, someone finally proposes that maybe the "murder victim" was "victim" only of a horrible series of coincidental accidents that lead to her death. This turns out to be true, but her parents can't accept that their daughter died from nothing but a series of random events. It's implied as the episode ends that they'll never give up trying to find a culprit.
- Fifty minutes (out of a usual 60) into the new Battlestar Galactica's season 2 finale, everything seems back to normal, even if our heroes had to rig an election to do it. Then the fraud is exposed, and the episode runs an extra 30 minutes to end on a cliffhanger for the next season to resolve, being the series' first extended episode.
- The real-time format of 24 means that most of the major action scenes don't take place until three-quarters of the way through any given hour (with very few exceptions). Also, any time an episode's final split-screen is shown with three or four minutes remaining before the beginning of the next hour (especially in later seasons), it's a sign that there's one more scene afterwards (usually as a cliffhanger). Somewhat surprisingly, this is fairly often lampshaded by characters saying something like, "I'll be there to meet the shipment at the docks in 20 minutes." If the viewer checks her watch, and it's 9:35, she can be pretty certain something important/exciting/surprising will be happening at said docks.
- Pretty much any of the early episodes of Star Trek: Voyager where they would stumble across gateways, wormholes, or advanced alien technology which gave them the possibility of getting home early. If it happened in episode #2 of series #1 you didn't need to wait for the 60 minutes to be up to know they were going to get the Negative Space Wedgie in the end.
- House usually hits upon the right diagnosis when there's about ten minutes of episode left. If the Patient of the Week seems cured before that, it's generally safe to assume that their condition is about to take a serious nosedive.
- There was actually one episode where there were actually numerous patients, and he had cured one less than half-way through the episode.
- NCIS usually starts each segment with a brief snippet showing the last few seconds of the segment in mute monochrome. At least twice, they've put stingers in after the snippet shown in the last segment of an episode.
- The Stargate SG-1 episode "Foothold". Carter runs away from the base, convinced that it's been taken over by aliens. O'Neill and Daniel track her down in Washington and tell her that she's been exposed to a paranoia-inducing chemical. You might believe them and think the whole episode is a Mind Screw... except that it's only halfway over, so they can't possibly be telling the truth.
- Subverted in another episode. We're at the 55-minute mark, bad guys are pounding on the door, the team is frantically working on the Applied Phlebotinum they need to escape—in other words, just a normal day in the life of SG-1 -- and then the bad guys break through the door, the team is captured in seconds, a Big Bad is revealed, and they spend the next episode trying to escape from a far worse situation.
- There is a possible aversion in the third season opener of Criminal Minds. They arrest someone about fifteen minutes in, and what follows is an infuriating sequence of questioning whether or not he is the killer. At the end of the episode, it's very likely that the man is the real killer, but it's still uncertain. The point of the episode ends up being the self-doubt the case creates in one of the characters.
- There's a definite inversion in the season five opener: the UnSub of the Week is discovered and then caught in the first 25 minutes, but the audience really doesn't care, because they're all waiting to find out if Hotch survived what looked like a point-blank shot to the head. During the investigation, Prentiss goes to look for Hotch, and finds his blood-spattered apartment, with him missing. Then Prentiss, Reid, and Garcia work the "regular" case in conjunction with searching for Hotch, and it's only when the case is finished that Reid tells the rest of the team that "something's happened to Hotch". The rest of the episode is devoted to resolving the cliffhanger from " . . . And Back".
- However, all other episodes are definitely played straight, but not so much with catching the criminal; it's usually obvious who the killer is by two-thirds of the way through. This trope applies to catching the killer before he kills the next victim. Will the cute blonde die before the team gets there? Nah- only seven minutes left in the episode. She's safe.
- Subverted in Farscape, as Crichton finally makes it back to Earth in the middle of a season, rather than in the series finale as might have been expected. Fortunately, by the time this happens the premise of the show had expanded enough that there were still plenty of stories to tell.
- One of the first episodes of Stargate Atlantis featured the gang stuck in a ship that was stuck halfway in a Stargate. They attempted to rachet up the tension by reminding the viewers that the gate would automtically close after 38 minutes, severing the ship in half and killing them all. However, given that they were only a couple episodes into the first season, and there were no Red Shirts on the ship, it was pretty obvious they were all going to make it out alive.
- Hidden tracks. On a CD, you can clearly tell if a song finishes many minutes before the actual track is finished that there will be a hidden track. On a vinyl record you can easily see more grooves, and on a tape you will see there is still some of the tape left to go. Obviously, it doesn't work at all on digital as you can clearly see the "song" is 20+ minutes long, leading to iTunes either indexing the hidden tracks separately, or keeping them as they are but making them album only due to the track length.
- One aversion is digital music provider Bandcamp: content providers are able to make hidden tracks a complete surprise; you'll only notice them once you've opened the compressed file you've just downloaded. Minecraft composer C418 included a six-minute song "What now?" as a hidden track for his album Life changing moments seem minor in pictures, for example, but you won't see it listed on the site.
- Album credits can sometimes give away certain aspects of an album in advance of the person listening to it. For example, the musicians credited can give away that a song contains a string section or a trumpet solo before the person hears it, while the lyric sheet can give away that certain tracks are instrumentals.
- Listening to a song on a media player that features a waveform visualisation (such as SoundCloud's audio player) can lead to this: if there's a sudden drop in amplitude about one minute in, you know in advance that there'll be a Subdued Section there, while conversely a sudden spike in amplitude means the song's going to get really, really loud all of a sudden. Owing to the Record of Loudness War, an increasingly large number of songs will have a fairly uniform amplitude for the duration of the song, averting this trope (but not exactly to desirable effect).
- Whenever a major title match is announced as the main event on one of the weekly shows, check the time. If there's only 5 minutes left on the show, it's almost guaranteed that the match will likely end in a disqualification or the defending champion winning through some sort of tomfoolery. Or, if it's a regular main event ad there's still plenty of time left after the winner celebrates his victory, expect someone to come out and cut a promo or attack them.
- In an article written years ago by sportswriter Phil Mushnick in TV Guide, he complained about the same-day, time-delay broadcasts of the Olympics (and other sports) spoiling the endings. The specific instance mentioned was a tennis match, and although the announcers were asking, "Will X make a comeback?" there were only five minutes left in the broadcast, so of course there wouldn't be a comeback, because there wasn't enough time. If there had been a comeback, they would have edited it so there would be time.
- In Act 5 of Henrik Ibsen's Peer Gynt, Peer has been shipwrecked and he and the only other survivor, a mysterious stranger, are clinging for dear life to a piece of wreckage. As Peer calculates his chances for survival and bemoans his fate, the apparently Genre Savvy stranger assures him he has nothing to worry about since he's the hero and "You can't die in the middle of the fifth act." Before Peer can ask what this cryptic remark means, the stranger loses (or perhaps releases) his grip on the wreckage and slips beneath the waves.
- Lampshaded multiple times in Urinetown, particularly:
Little Sally: (wistfully) She loves him, doesn't she, Officer Lockstock?
Officer Lockstock: Of course she does, Little Sally. He's the hero of the show--she has to love him!
- It's considered an Idiot Ball by some to go reading a tropes page for a work before seeing/reading/etc the work, and expecting not to be spoiled. The pages explain the tropes in a work, so why anyone would read over them before seeing the work is odd. The spoiler tags still spoil, though, because when you come to a heavily spoiler-tagged section that deals with a specific character, you're going to know something is going to happen when the character turns up - even if you're not sure what.
- Or if the gender is constantly hidden by spoilers, especially if the male-to-female ratio isn't equal. If a work has 3 male characters and 1 female, and you see that The Mole's gender is constantly hidden, you can make a pretty good guess who it's going to be.
- Subverted by Portal, along with Interface Spoiler. The New Game level selection menu clearly shows a list of the test chambers, which make up only the first half of the game.
- Blue Dragon kills off Nene. Except not really - this is on the end of Disc 1. You know there's more coming.
- As mentioned in Disc One Final Dungeon, a lot of the time you know you haven't really defeated the Big Bad and saved the world because you have three more discs to go through.
- Subverted by La-Mulana. While you can look around the game's files and hear the soundtrack and see the graphics for all the levels and bosses... The graphics for that cutscene are all mixed up.
- See any Youtube fighting game video. If the vid isn't even halfway done when the second round starts, expect whoever won the first round to lose the second round, setting up a third round with everything at stake. If the vid is more than halfway done when the second round starts, well, it's a safe bet that the second round is going to be the final round.
- The same applies for any Pokémon battle: If the opponent is down to his or her last Pokémon, you can tell the uploader will win if there isn't much time left, but if there's ample time, the opponent will cause a comeback (though the opponent won't necessarily win).
- Persona 3 does all kinds of things with this trope. Ostensibly, the game takes place over one year in game time, beginning in early April and ending at the end of next March.
- Played Straight: You defeat all of the main arcana shadows in early November. There's still 5 months left to go...Hmmm...
- Subverted: The final battle to stop The End of the World as We Know It takes place on January 31st. You don't do anything for the next two months, as you skip right to graduation for the Golden Ending.
- Tales of Monkey Island Chapter 4 seems to wrap everything up...until you realize there's a fifth chapter. It involves getting killed and wandering around the afterlife which includes several rehashed elements disguised as portals. Naturally, you have to enter the real world, return to your body and face the Big Bad again at the end.
- In the Professor Layton series, the game isn't close to ending if most of the mysteries are still unsolved, and if any of them have not been introduced yet. This is especially true with the Disc One Final Dungeon in Unwound Future. Additionally, the closer the numbers of the main story and optional puzzles are to the hidden puzzles, the closer you are to the end.
- Unwound Future later subverts this though: some of the mysteries are solved during the ending cutscene. (so technically the game is already over)
- Batman: Arkham City has the character profiles. The number of side quests verses the number slots means you still have to meet a few people.
- The Gödel, Escher, Bach scenario is referenced in this Irregular Webcomic strip's annotation, and indeed it does the same thing itself.
- Subverted by a Penny and Aggie storyline, in which a chapter numbered "N of 15" suddenly has a quintuple-length Wham! Episode on the 11th update, marked "page 11-15".
- This comic of Full Frontal Nerdity references the trope.
- Lampshaded in one video by Stuart Ashen, on the subject of the fastest game-overs in video game history:
- Made more funny in that his first video on the quickest game overs ended with about the same amount of the time as when Leisure Suit Larry beat Grange Hill's record, so time is padded out with footage of the drug dealer Have a Nice Death scene without any reference to the time remaining in the video.
- Television Without Pity will occasionally snark about the episodes they are recapping in this fashion. For example, in House, when House makes his first misdiagnosis, the recapper might say something to the effect of: "Since this is just the 15-minute mark, we know that whatever treatment he's prescribed will just make things worse."
- Subverted by Slowbeef in his Let's Play of Metroid Prime, who inserted six minutes of blank filler at the end of a boss fight video to keep viewers from guessing what happens based on how much time there's left in the video.
- Mentioned in Mark Reads New Moon chapter 16. In the previous chapter, Bella had attempted suicide, leading Mark to hold a GIF party in celebration. There are 24 chapters in the book, however, so Mark is in no way surprised when she's saved.
- A similar point was made during a sporking, when it was commented that Bella might as well say "Goodbye, I love you, because of course I'm not going to survive this even though there are 200 pages left in the book and it's told in first person."
- Rooster Teeth's Achievement Horse series. Take a quick look at the video time, and you can tell from the start how close a game it's going to be.
- Lampshaded on The Simpsons; "Who Needs The Kwik-E-Mart?"
Homer: "Everything's wrapped up nicely. Ooh, much quicker than usual, too!"
- Full-season version. In Avatar: The Last Airbender, the final-battle invasion on the Day of Black Sun was scheduled to be episodes ten and eleven out of twenty (later discovered to be twenty-one). Were they going to win and spend the next ten partying?
- Well, they did do some partying... In any case, attentive viewers would've caught Azula finding out about the invasion in season 2. There was pretty much no way it would've worked.
- Minimum - it's certainly not unheard of for one final decoy to be introduced then, with the real culprit caught even later.