Reverse Mole

The reverse of The Mole. A villain, usually a henchman, turns out to have been a goodie all along.

To avoid becoming the Deus Ex Machina; there must be Foreshadowing and he may have had to do something horrible to get the villains' trust; good guy or not, he may never be able to go back.

Related tropes include Fake Defector -- wherein a hero pretends to undergo a Face Heel Turn -- and The Infiltration, wherein a hero disguises themselves as a completely different person who joins the bad guys.

A subtrope is the Stealth Mentor, who reveals that they have been opposing the hero all along as a way of forcing the hero to become stronger.

Compare Heel Face Turn and Mook Face Turn. If the villain forces the goodie to join him, it may be a Sadistic Choice or I Will Punish Your Friend for Your Failure.

Anime & Manga

 * in Magical Girl Lyrical Nanoha StrikerS, who despite having been modified into one of Jail Scaglietti's minions, still planned to eventually stop Scaglietti. The Omniscient Council of Vagueness notes that he would have been their perfect observer for Jail.
 * The random, forgettable Agent with sunglasses in Elfen Lied who was secretly working as a mole for the not-so-good guys of the Japanese government in order to steal information about their Diclonius propagation plot and hopefully a vaccine if possible, as well as cover up their own asses.
 * Fullmetal Alchemist:
 * Bleach has . Notable for being under deep cover (he was the only one who knew his agenda, though it has been hinted that   knows more than he's let on...) for at least a hundred years, during which he actually managed to make really high in the evil hierarchy.
 * This ends up a Double Subversion. The Audience is nudged into thinking that he's the bad guy from the very beginning, especially after . Then, when , there's all of two minutes of thinking that the whole thing was just a convoluted misunderstanding, before we find out   THEN we find out much later that   was actually one of the good guys, albeit a "good guy" who will do very evil things for the greater good.
 * A more accurate term would probably be zigzagged, as  Although, this still tends to be under debate.
 * In Sekimatsu Occult Gakuin,  until it's revealed that
 * Itachi from Naruto. Too bad it was only revealed once he was dead.
 * Tsubasa from Metal Fight Beyblade infiltrates the Dark Nebula organization on behalf of the WBBA under the pretense of being a mere mercenary looking to sell his services to the highest bidder.
 * In the thirteenth Pokémon movie, Zoroark: Master of Illusions, we find out (pretty early on) that.
 * In One Piece, Vivi infiltrated Baroque Works along with Igaram to find out who was the boss trying to destabilize her country and managed to stay hidden for two years before she was discovered.
 * Gajeel from Fairy Tail was shown, shortly after his supposed Heel Face Turn, conspiring with Raven Tail. Then it turns out that he's actually on Fairy Tail's side after all, and is only pretending to work with Raven Tail.

Comic Books

 * As soon as Chris Claremont returned to the X-Men, he revealed that Tessa (aka Sage) had been a Reverse Mole for the X-Men... for the first 20 years of her editorial history!
 * In Marvel Comics, The Shroud has been undercover as a supervillain since the '80s, even going so far as to form the Night Shift, a team of supervillains with no idea their boss is working to destroy the underworld from within.
 * from the Boom Kids Darkwing Duck comic.

Film
"So what, you're a triple agent?
 * Alfred Hitchcock's Mistaken Identity film North By Northwest features a mole inside the crime syndicate. Naturally, it's the Femme Fatale.
 * Willy Wonka and The Chocolate Factory:.
 * Austin Powers Goldmember: #3 is a mole for British Intelligence, and has a huge mole on his face. Hilarity Ensues.
 * Indy's partner Mac in Indiana Jones and The Kingdom of The Crystal Skull goes from The Mole to a Reverse Mole to over the course of the movie.
 * Nope, he was always a mole, Indy just bought his spiel about working for the CIA.

No, I just lied about being a double."


 * More like a Bait And Switch Villain, the director of intelligence in Starship Troopers 3 Marauder is initially seen by one of the protagonists (and the audience) as a traitor who's trying to assassinate the Sky Marshal, covering up the failed attempt and preventing his rescue, and seizing power. Well, she actually is doing all that...because the Sky Marshal has gone nutty (well, nuttier) and is going to sell humanity out to the enemy.
 * In Running Scared, the two protagonists seem about ready to be gunned down by gangsters fairly early in. Lo and behold, two of the bad guy's Mooks turn out to be undercover cops and rescue them.
 * turns out to be this in the film adaptation of The League of Extraordinary Gentlemen. The weird novelization of the film even has him explain that he's a member of the British Secret Service.
 * In Ip Man 2,  appears to be a minion of the brutal British at first, until he turns out to be working for their arrest. Foreshadowed by
 * A One Nation Earth officer in the Apocalypse film series movie Tribulation shows up in a Christian hideout ready to kill all the Christians in it, but as it turns out only fires blanks, revealing himself to be on their side.

Literature

 * Harry Potter:
 * Ulic Quel-droma started out this way in the Star Wars EU. The Dark Side being the Dark Side, however, he can't keep up the charade.
 * All loose ends are tied up at the end of James Thurber's masterpiece of whimsy The 13 Clocks when
 * GK Chesterton subverts the hell out of this trope in The Man Who Was Thursday: the protagonist himself infiltrates the Central Council of Anarchists, then gradually discovers that.
 * Someone surprising does this to the Zhentarim in Crown of Fire (a Forgotten Realms novel).
 * in The Secret of NIMH is probably only working for evil under threat of coercion, so it's not surprising that he pulls a Heel Face Turn at the last moment. Unfortunately, Redemption Equals Death.
 * That one guy in one of the New Tom Swift books (Tom Swift and his Jetmarine, I think)...I don't remember his name, though.
 * Hey, I remember that guy! It was the "Jetmarine" book, and they thought he was a Kranjovian agent or something.
 * The titular assassin of The Day of the Jackal is hired because the organisation plotting de Gaulle's death is so full of Action Service infiltrators that its head is confident of the loyalty of only two others.
 * In Edgar Rice Burroughs's The Chessman of Mars, a character suddenly comes to Turan and Tara's aid, and reveals that he was one of the Gathol slaves held captive there.
 * The plot of one of the first spy novels, Fenimore Cooper's The Spy ends with this revelation, via a cameo appearance by.
 * Wheel of Time's
 * The protagonist of Kurt Vonnegut's Mother Night. Sucks for him that the good guys he helped won't admit what he did after the war ends.
 * Not that it would have eased his conscience much if they did.
 * In the second half of the Sherlock Holmes novella The Valley Of Fear,  turns out to be an undercover Pinkerton detective.
 * In Andy Hoare's White Scars novel Hunt for Voldorius, Malya, forced to serve as Voldorius's equerry, sends information to his foes.
 * In Elvenborn, due to his impressive knowledge of tactics and ingenious training methods the reclusive young Kyrtian V'dyll Lord Prastaran is placed in charge of the Elvenlords' side of a civil war instigated by the hated half-human Wizards. Not only would House Prastaran probably be destroyed root and branch if the High Council even had a hint of their attitudes toward human-elven relationships, but.
 * In Warrior Cats, Ivypool becomes one of these after she learns that the Dark Forest, a place where she is training, is plotting to destroy the clans. She stays with the Dark Forest so that she can give their information to Jayfeather, Lionblaze and Dovewing.
 * In Warrior Cats, Ivypool becomes one of these after she learns that the Dark Forest, a place where she is training, is plotting to destroy the clans. She stays with the Dark Forest so that she can give their information to Jayfeather, Lionblaze and Dovewing.

Live Action TV

 * In the episode Into the Fire, a Reverse Mole is the only reason Colonel O'Neill of Stargate SG-1 doesn't have a snake in his head.
 * Indeed, most Gou'ald System Lords have a few Reverse Moles in their fleet, either one of the Tok'ra or Jaffa who believe the truth about their "gods"- namely, that they are, in fact, Always Chaotic Evil snake-like parasites inside human bodies.
 * Doctor Who has Dalek Caan in "Journey's End".
 * In Attack of the Cybermen, one of the gang is actually a police officer.
 * in the latest season of 24.
 * Tuvok at the start of Star Trek Voyager infiltrated the Maquis...though how is left to the Expanded Universe.
 * Get Smart used a twist similar to The Man Who Was Thursday in one episode.
 * Gaeta on New Caprica in Battlestar Galactica.
 * Flash Forward executes a perfect Reverse Mole when This is also an example of Lampshade Hanging, as the character's name recalls.
 * In V-2009, Joshua and several other crew members on Anna's ship are members of The Fifth Column.
 * The First V had a fair amount of The Fifth Column as well, some of them high-ranking. Seems a lot of the Visitors weren't very happy with their orders.
 * Colby of Numb3rs was revealed to be a double agent for the Chinese in Janus List. But then it turns out that he was really working for the FBI in the following episode.
 * In the pilot episode of Nikita, Naive Newcomer Alex is revealed to be a mole for the eponymous hero so that she can keep tabs on her old employers at Division.
 * While not done in the direct sense, the same principle is used on Hustle frequently with a random character turning out to be part of the con.
 * Colby of Numb3rs was revealed to be a double agent for the Chinese in Janus List. But then it turns out that he was really working for the FBI in the following episode.
 * In the pilot episode of Nikita, Naive Newcomer Alex is revealed to be a mole for the eponymous hero so that she can keep tabs on her old employers at Division.
 * While not done in the direct sense, the same principle is used on Hustle frequently with a random character turning out to be part of the con.

Tabletop Games

 * Warhammer 40000:
 * The Green Lady in Exalted.

Video Games

 * In Super Smash Bros Brawl,
 * In Fire Emblem: Blazing Sword, Leila is one..
 * in ~Assassin's Creed~ is an employee of Abstergo Industries, an organization run by the Templars It's revealed at the end of the first game that The third game in the series, Brotherhood, drops some hints that
 * from Lunar: Eternal Blue really seems to enjoy egging on the heroes...but that's because he secretly thinks they're the only hope against his boss, the Big Bad.
 * In Wild Arms 2, Antenora, Vinsfield's lover,
 * Lapis Roman from Xenosaga appears to the player at first as a no-nonsense and brutally efficient Galaxy Federation officer who arrests all the playable characters. Later, during her "interrogation" of the prisoners, she reveals that she's working for the good guys, and helps them devise an escape plan and a way to clear their names.
 * Done in Secret of the Stars, where
 * The real hero of Metal Gear Solid One, Two, and Four?
 * Also, in Metal Gear Solid 3,.
 * Half-Life -
 * In Blue Dragon, Nene reveals that was working for him all along...
 * in Mirrors Edge seems to be in league with the Icarus conspiracy (or, at least, in their pocket) but actually has his own agenda and assists Faith in the final level.
 * in MegaMan Star Force 3.
 * Knights of the Old Republic: sure, you could act like a typical Sith student in the academy on Korriban, but for light-siders, it's often much more satisfying to quietly sabotage the Sith's every action from the inside out (for example, knocking out the Mandalorian prisoner at his request instead of torturing him, letting the rebellious students escape, calming a self-destructive droid instead of scrapping it, etc.), and still get the prestige that you would've gotten if you had actually been evil.
 * Let's not forget committing the ultimate in "destroy from within".
 * During the Underdark episode in Baldurs Gate 2, if you choose to spare Solaufein when Phaere wants him dead, he'll reveal that he's a follower of Elistrae, one of the few good-aligned deities of the drow pantheon, and is struggling to find redemption for his people.
 * In Final Fantasy Dissidia,  turns out to be working for Cosmos, and serves as a Stealth Mentor to a few of the heroes.   was also one of these with a similar role in the prequel, but Kefka found out and loaded him up with malicious Fake Memories to get him to knock it off for the events of the original.
 * In Danger By Design, Nancy finds evidence that a Frenchwoman thought to have been a WWII collaborator was actually covertly working to preserve and conceal some of France's artistic treasures.
 * Crimson Viper of Street Fighter IV appears to be one of S.I.N.'s Punch Clock Villains, but in actuality, it's hinted several times that she's actually an undercover CIA agent.
 * This is outright stated in her profile for Marvel vs. Capcom 3.
 * In Blaz Blue, starts out as an Intelligence operative for the Novis Orbis Librarium, but upon discovering the Awful Truth about , works as Reverse Mole for Sector Seven.

Web Comics

 * Bob and George here and
 * Sluggy Freelance: Torg's purpose for joining the Minion Master in the first place, not to mention the various supervillain organizations he infiltrates.
 * Possibly Dr Schlock's motive for taking over Heretti-Corp; in spite of Becoming the Mask he does keep the villainy minimized, and feels regret for the damage he's responsible for.

Web Original

 * Whateley Universe: The Necromancer's Children of the Night had a Reverse Mole: Vamp, who likes to think she's the Femme Fatale.

Western Animation

 * The New Batman Adventures episode "You Scratch My Back" has Nightwing acting as this to fool Catwoman into Batman's plot of bringing her and the villain of this episode in.
 * Teen Titans played with this trope in the first season finale. Slade reveals his season-long Evil Plan to Robin: Slade had . After this reveal, Slade, thus making Robin somewhat of a Fake Defector, albeit Following the establishment of his apprenticeship under Slade via a little crime spree and a show-down with his ex-teammates Robin's friends fully believe that he has been lost to The Dark Side, for good. This makes the discovery that Robin was really   all the more surprising, from their P.O.V.
 * In The Simpsons, Lisa enters a singing contest hosted by Krusty, with Homer as her manager. After she fires Homer for being a Jerkass, he begins managing her competitor... who then loses all his fans and popularity in the final. Homer shows himself to be a Reverse Mole to Lisa at the end.
 * Avengers Earths Mightiest Heroes:.

Real Life

 * Several of these examples popped up following World War II, where many Quislings in countries occupied by Nazi Germany turned out to have been helping their countries' La Résistance all along.
 * Or so they claim.
 * More significantly, Abwehr, the chief intelligence agency of Nazi Germany, was filled to the brim with Double Agents and Reverse Moles, including Da Chief himself, Admiral Wilhelm Canaris. Their various subversive acts included smuggling Jews out of Germany, feeding false information to the Wermacht, feeding true information to the Allies, and plotting the assassination of Adolf Hitler. It's no wonder then that German intelligence during World War II was extremely shoddy.
 * So was his follow-up. The Germans' overseas situation was not helped either by the fact that Abwehr's 'finishing school' tutor was in fact an MI 6 plant, which meant that virtually every agent was rounded up on day 1, and most, due to their misgivings of NAZI ideology were easily turned.
 * Really, any real life The Mole is someone's Reverse Mole.
 * ATF agent Jay Dobyns is one of the more successful undercover cops in history, being the only one to have risen to full-patch member of the Arizona Hells Angels. Made doubly impressive because he was a extremely successful college football star in the same state.