Heel Face Mole

"''Once a rabbit wanted to get to the other side of the lake. A crocodile told him, "You can ride on my back."

"But you will eat me", responded rabbit.

"I will not, I've changed," said crocodile. So rabbit sat on the crocodile's back. But when they were in the middle of the lake, crocodile started to eat rabbit.

"You lied to me!" screamed rabbit.

"I'm a crocodile. What were you expecting?""

- Don Diego de la Vega, Zorro

A villain has finally seen the error of their ways and converts to the side of good... but surprise! They were actually The Mole after all, suckers!

Compare Fake Defector and the Civilian Villain. Contrast Reformed but Rejected. See also Becoming the Mask.

Anime and Manga

 * Umineko no Naku Koro Ni has this in the form of.
 * King Zarkon did this as the Shocking Swerve for the Voltron revival, Voltron: The Third Dimension.
 * Schreient of Weiss Kreuz use this ploy on Weiss by having Neu pose as Yoji's dead partner Asuka, revived by a Mad Scientist and amnesiac, in order to lure Weiss into a trap. Nastily enough, the series hints that Neu is in fact Asuka, but she dies for real without ever realizing that fact.
 * In Transformers Robots in Disguise, the Decepticon subgroup claims that they want to defect from the Predacons and join the Autobots. (Since the Decepticons, in this continuity, are actually reprogrammed Autobots, this isn't as unlikely as it sounds.) Optimus Prime welcomes them happily, but their leader's acting abilities aren't quite up to the job, and he reveals that it's a scam just before the Decepticons can find out where the Autobots' secret base is.
 * In one episode of Inuyasha, Sango's brother Kohaku appears to be free from being brain-controlled, Identity Amnesia included. However, at the end of the episode we see that he's still controlled by Naraku, since it was all part of his insidious plan.
 * In Pokémon Best Wishes
 * Ash's Pikachu didn't buy it for a second, glaring at him constantly.
 * Ash's Pikachu didn't buy it for a second, glaring at him constantly.

Comic Books

 * The Pre Crisis Luthor did this repeatedly. Because they were friends in their youth, Superman would usually give him a fair chance, even though he knew he could never fully trust him. In one famous "Imaginary Story" by Jerry Seigel, this led to Luthor actually killing him.
 * Martinez turns out to be a mole for the Governor of Woodbury in The Walking Dead after he helps them escape the town safely. And gets run over for it.
 * Played with in Villains United, the prequel to the current volume of Secret Six. is recruited to the Society, and reveals herself to be both The Mole and . As it happens, though,.

Film

 * Indiana Jones and The Kingdom of The Crystal Skull..
 * The wife of the terrorist in Collateral Damage betrays him only to reveal she was just doing it to infiltrate the CIA.
 * In the second (or third) Fantastic Four movie, the Four are assisted in the Silver Surfer's capture by . They were reluctant at first, understandably and for good reason.

Literature

 * In Nineteen Eighty-Four,.
 * In one of the earliest Babysitters Club books, the girls are losing clients to the Baby-Sitters Agency (mainly because their members are older than twelve), so Kristy tries to find some new members. The two she gets are Janet and Leslie (?), who apparently quit the Agency because they didn't like how it was being run. So they're promptly booked for jobs with two new clients who saw the club's advertising for new, older sitters who could stay out later. Imagine the girls' shock at the Monday evening meeting, when their "defectors" don't show up, and the new clients call to complain that they were stood up. Kristy was absolutely devastated when she confronted them and learned that they did it deliberately to sabotage the BSC's reputation.
 * Also subverted in Flashman and the Angel of the Lord. was supposed to sabotage John Brown, but ended up following him for real.
 * Happens in the classic Uncle Remus tale Brer Possum's Dilemma.

Live Action TV

 * Subverted in Lost: Juliet was set up to do this but, unknown to Ben, she had turned for real.
 * Season 6 of 24 opens with a terrorist apparently turning traitor on the leader of his organization, offering his location to CTU so he can be assassinated. In fact, the "leader" has forsaken terrorism, and the traitor, the new mastermind of his organization, is trying to have him eliminated to further consolidate his power.
 * Almost all of Mulder's informants in The X-Files are in fact loyal agents of The Consortium, engaged in a disinformation campaign to keep him distracted from what they don't want him to find out.
 * Kashyk, the charming Devore inspector from Star Trek Voyager's "Counterpoint", defects from his species and seeks asylum aboard Voyager, romancing Janeway to get her to trust him..
 * does this in Battlestar Galactica in order to.
 * Irina Derevko in Alias.
 * A version of this is present in Farscape. He's not necessarily the antagonist, but in the fourth season, the main reason Scorpius came on Moya was so that he could wrest the secrets of wormhole control from John's mind.
 * This happened in an episode of Get Smart, where Siegfried attempts to "defect" to CONTROL, going so far as to turn in several KAOS agents, including his own sister. Eventually he gives them fake data to divert security away from the CONTROL Chief's Banquet so he can use sleeping gas to kidnap all of CONTROL's leadership in one fell swoop only to be foiled by Max's lapel flower.
 * From Glee: Jesse St. James, who seemingly gave up his UCLA scholarship and position as lead male of Vocal Adrenaline for Rachel. Yeah, we'll give you a second to get over that shocking revelation.
 * Season 2 of Warehouse 13: H.G. Wells rejoined the Warehouse just so she could She does a Heel Face Turn for real after the incident though,

Video Games

 * Appears in several Squaresoft/Square Enix games:
 * Kain in Final Fantasy IV, is kidnapped by The Dragon early in the game and brainwashed into serving him. Partway through the game, he is "freed" from his control and rejoins the party. Later, it is revealed that he had been under control the whole time when he absconds with the crystal he had been aiding the party in recovering.
 * However, in the GBA and DS versions, when the crystal is retrieved, the new "Inner thought" feature reveals that The Dragon was in the process of taking his mind. Not sure if it's a subversion, but either way, he does betray you twice. This is probably due to better translation teams.
 * A lesser example is Beigan, who meets Cecil in Baron Castle and voluntarily joins the party out of loyalty to Baron... its current management, as Palom and Porom quickly expose him as an infiltrator. Cue boss battle!
 * Emperor Gestahl in Final Fantasy VI, who carries the farce to such an extent that his top lieutenant, General Leo, earnestly involves himself in the heroes' cause and refuses to turn on them when the truth is revealed.
 * Kefka claims that Celes is one when the heroes encounter him in the Magitek Factory. However, this is an outright lie, as Celes' Heel Face Turn was genuine.
 * Emperor Vondole of Secret of Mana pulls a similar stunt, but doesn't drag it out as long -- as soon as the heroes arrive at the planned conference with him, he throws them in the dungeon.
 * Wild Arms 3's first minor antagonist, Janus Cascade, does this fairly early on in the game by supposedly wanting to help Virginia find the Eternal Sparkle in hopes of redeeming himself for the scuffle on the train, but it turns out he just wanted one of the 3 masks that's the key to getting the Eternal Sparkle for himself. Well more like the Prophets, but still...
 * Well he's named after the Roman God who had 2 faces, so... what do you expect?
 * Kerrigan in Starcraft: Brood War, who successfully pulls this scheme on several rival organizations simultaneously, ultimately playing them off each other to consolidate her control over the Zerg Swarm. "Pretty much the Queen Bitch of the Universe," indeed.
 * Duran does that too. Twice.

Web Original

 * In The Gamers Alliance, Ferron defects to the Alliance's side after the Yamatian Invasion because his superiors in the dark clergy betrayed him and he wants revenge. Although he helps the heroes deal with his former colleagues and befriends many people in the Alliance, he has a far more sinister agenda in mind. He almost switches sides for real because of all the friends he has gained but eventually decides to subvert his character development and betrays the heroes at a crucial moment because his lust for power overshadows his growing friendship with the heroes.
 * Xerathas, Varalia and the Shadow also join the Alliance's heroes during the Vanna arc and claim they'll help the Alliance so that they can atone for their actions as well as prevent a greater threat from rising. Knowing what they're dealing with, the heroes don't buy the excuse but decide to let them tag along while keeping an eye on them. To the heroes' surprise the trio are surprisingly helpful during many encounters, which makes many Alliance members question whether the trio have finally seen the light. Everything changes during the battle of Vanna, however, when the three antagonists reveal the extent of their plan and betray the heroes at the Alliance's most vulnerable moment while the Alliance is busy dealing with another threat.
 * in Kate Modern, despite having secretly become a much nastier villain than before.

Western Animation

 * In the Ruby-Spears Mega Man cartoon, the evil Proto Man temporarily switched sides in order to cover up a plot of Dr. Wily's. (in the games, Protoman was never evil but only framed by Dr. Wily, but the writers either never beat Mega Man 5--Or Mega Man 3, where he first showed up and seemed to be a villain, but was later revealed to be a good guy--or ignored it for the sake of having a Evil Counterpart and Rival for Mega.)
 * Most likely it was the latter. If 7 had been released before the cartoon, Bass would have been Dr. Wily's offsider and Proto Man would have kept his canonical role of mysterious loner big brother. Probably. With that cartoon, you never know.
 * In 3, Dr. Wily repents and works with Dr. Light. It ends predictably.
 * The Super Friends fell flat for this when the entire Legion of Doom suddenly did a Heel Face Turn.
 * In the Captain N the Game Master episode based on Castlevania III, Alucard turned out to be one of these. This is not even close to the worst thing they did to his character.
 * A US Acres segment from Garfield and Friends had Gort pulling this on Orson and the gang.
 * Codename Kids Next Door had one of these in Op. U.N.D.E.R.C.O.V.E.R., where one of the Delightful Children joins the KND.
 * The New Adventures of Superman episode "Can a Luthor Change His Spots?" Luthor convinces Perry White that he's gone straight and is given a laboratory in the Daily Planet building. Jimmy Olson correctly believes that Luthor is lying and tries to catch him committing a crime.
 * Ursula from The Little Mermaid, according to her Villain Song.
 * actually becomes one at the end of Toy Story 3.

Real Life

 * Before the mass suicide at Jonestown, under pressure from a visiting U.S. congressman, Jim Jones allowed a group of people to leave the camp. Just as their vehicle was ready to leave, Jones loyalist Larry Layton demanded to join the group. He was allowed after a cursory patdown, over the protests of several defectors. They were right to be skeptical, as he later pulled a gun and shot two of them.
 * It is said (4.12.2) that during the First Messenian War, the Spartans sent a hundred soldiers to their enemies under the guise of deserters. They were all sent back after basically being told "please, Spartans, no Dead Horse Tropes."