It's not hard to see the attraction of The Mole
or the Face-Heel Turn
to a TV writer. The shadowy villain who's been plotting for several episodes is revealed - and it's a previously sympathetic character, providing a dramatic twist with just a silent shot of his face. However much inherent drama there is in these tropes, they also pose a big problem in the long term. Having one of the characters turn out to be a villain either rips the heck out of your cast structure, makes your characters look like idiots, or both. Repeat the trope and it's even worse.
Hence the much milder form described here. Something bad still happens, the characters still chase around looking for the culprit, and it's still one of them, plotting behind the scenes. But he's doing it with the best of intentions, hoping that whatever he's done will help them all. Usually he's right, and he's grudgingly thanked. Sometimes he's wrong, and has caused a complete disaster - but he's still not a villain.
- Jesus asks Judas to betray him in The Last Temptation of Christ, thus fulfilling a vow Judas had made before Jesus took up the role of the Messiah, when he was just a carpenter making crosses for the Romans to crucify Jews upon.
- The rock-opera Jesus Christ Superstar portrays Judas as someone who was simply too practical for the radical and mystical elements of Jesus' movement, and overly concerned with the size of the movement possibly drawing attention from Rome. He has not one but two monologue songs where he agonizes over his motives. One needs only to look up the lyrics to "Heaven on Their Minds" to see a clear example of this portrayal.
- He's also concerned about the Cult Of Personality surrounding Jesus, believing the man is putting himself above the movement.
- There's also the interpretation that, since Jesus' sacrifice was part of the Divine Plan, Judas was an instrument of the will of God. In some dramatic productions (e.g. John Neumeier's ballet) Judas is actually too remorseful to deliver the traitorous kiss, and it is Jesus who deliberately forces it.
- The play Godspell also takes this route, and if done well, the look on Judas' face as he narrates the betrayal will break your heart. Also slightly different from the above in that Jesus knows what is happening but simply tells Judas "do what you must" at the appropriate moments to push events in the right direction.
- The original Judas Iscariot is often considered to have had unselfish intentions — perhaps he wanted to goad Jesus into all-out war with the Romans to liberate the Jews. And the pseudopigraphical Gnostic Gospel of Judas actually claims that Jesus ordered him to do it (going by the accepted Gospels it wouldn't have been so much that as giving permission, because Jesus knew it had to happen anyway.)
- This also comes up in Lamb: The Gospel According To Biff, Christ's Childhood Pal. Judas is a member of the Jewish zealots and perhaps a little bit of a jerk, but otherwise loyal to Jesus/Josh. Josh not only singles him out for the role turning him over to the Romans, but also whispers instructions to him on how to do it. The novel doesn't even consider his act a betrayal as it was not only Josh's wish, but also an integral part of his plan for mankind's redemption.
- Jorge Luis Borges took this a step further, positing a mock-theory that Judas was the real Messiah; Jesus just sacrificed his mortal flesh, but Judas knowingly damned his soul in order to redeem humanity. Since this was presented as the final absurdity of a fictional academic in a fake academic essay, there's no way of knowing how seriously Borges took the idea.
- The Gospel of Luke suggests that Judas was possessed by Satan at the time. Go figure.
- Which is interesting because in all of his earlier appearances, Satan is depicted as a servant of God. The Book of Job has him asking God's permission to test Job.
- That only indicates he is subservient to God, i.e. he has no authority and whatever he wants to do he has to get permission.
- Which seems to be basically the same thing.
- John Brunner's story "Judas" (1967), from Dangerous Visions, retells the story in a futuristic context.
- House provides the name of the trope, from an episode title. Someone sells Dr. House out to the cops. He investigates his sworn enemies (i.e. the rest of the cast), but it turns out to be Wilson, his only friend, desperately trying to save him from prison. Wilson even asked the cop for "thirty pieces of silver" to complete the allusion.
- Studio 60 on the Sunset Strip: A question about patriotism is inserted into a focus group, spurring Matt to be even more politically controversial than usual while trying to discover which timid executive was responsible. It was Danny, of course, using reverse psychology.
- Buffy the Vampire Slayer: What villain called up the undefeatable, lethal, musical demon, and what dark scheme were they plotting? Xander Harris, and he just wanted a musical-comedy ending to all his friends' problems.
- The West Wing: Who leaked Leo McGarry's terrible debate-preparation tapes to the press? Leo McGarry himself, to lower expectations.
- Also occurs in a series six-seven subplot where someone in the West Wing leaks details about a military space-shuttle project during a potentially lethal crisis on a space station, which Toby is asked to investigate. Turns out it was Toby himself who leaked it, in order to hasten the rescue of the astronauts on the station. He's promptly fired, prosecuted for revealing federal secrets, and only very reluctantly pardoned by the President when he leaves office.
- When it's not considered Fanon Discontinuity, some fans theorize that CJ was the leaker (since all the clues do point to her anyway), and Toby figured it out and took the fall because he was, at least a little bit, in love with her.
- There were examples in Sorkin-era episodes too — "Take Out the Trash Day" (Leo's drug addiction; it was some intern, whom Sam fires with extreme prejudice and Leo kindly unfires); "Enemies" (the president told the vice-president off in a cabinet meeting; everyone thinks it was the VP himself, but C.J. figures out it was the secretary taking minutes); "Bad Moon Rising" (something about the president supposedly changing his position on school vouchers; we never find out who it was, because the whole storyline is a study in Toby's state of mind); and "War Crimes" (a quote from Toby about the president being politically beholden to the vice-president; ditto).
- Subverted in Murder One: A member of the defense team humiliates the prosecution by "leaking" them a pornographic videotape that looks like a vital piece of evidence. The lead defense lawyer figures out who's responsible for the "leak", has a good chuckle about how it worked out in the end... and fires him on the spot for unethical behavior.
- 24. Pretty much any major character fits this trope at some point. Jack does it several times each day.
- Wesley trying to prevent Angel from eating his son, as prophecy said he would. Didn't go well.
- Cordelia unwittingly became Jasmine's corporeal agent on the Earth, gradually losing her entire personality in the process. It was so subtle than no one in Angel Investigations noticed until she was too forgone to save.
- In Dollhouse, the end of the series reveals that Boyd is the mysterious founder that everyone assumes is the Real Villain. Turns out he wants to use Caroline's spinal fluid to create a vaccine against imprinting. In hindsight, maybe that wouldn't have been such a bad idea, but (a) he had a Well-Intentioned Extremist way of going about it and (b) he's partially responsible for the rise of imprinting technology, so it's his own fault that the vaccine would be needed in the first place, so he dies thought of as a villain.
- In the Star Trek: The Original Series episode "The Menagerie", Spock actually steals the Enterprise, maroons Kirk on a starbase, and then decides to go to the one place in the whole of the galaxy that is considered forbidden territory in the Federation. Turns out he was on a mercy mission. Kirk's response is something like, "Oh. Well, all right then."
- Zig-Zagged in the new Battlestar Galactica. Virtually every plot in the series revolved upon who was betraying whom.
- In NUMB3RS, the team is investigating several deaths caused by a disease thought to be wiped out. In the end, the culprit ends up being one of the scientists responsible for looking after the remaining strains of the virus. He thinks that another outbreak was inevitable, and by infecting a few people, it would force doctors to find a cure and prevent an epidemic in the future. In fact, the team finds him leaving flowers on the graves of his victims.
- Happens in one of the Ace Attorney games (Trials and Tribulations), where the defendant is revealed to have received a blackmail letter calling her out to a remote shack in the mountains, and threatening to reveal her 'secret' if she didn't comply. Who was responsible for this nefarious deed? Why, it was Casanova Wannabe Larry Butz, who considered the letter to be a romantic gesture. The secret he was going to reveal was the (completely imagined on his part) love between them.
- This happens in Sluggy Freelance when Riff is revealed to be a Hereti Corp employee during "Dangerous Days."
- In We're Alive much of the second season is spent looking for The Mole who betrayed the Tower to the Mallers. The third season reveals that it was Kalani but that he only did it because the Mallers had his daughter held captive.
- The Simpsons: Mr. Burns orders Smithers to take a hit out on Homer Simpson after Homer sends him a nasty letter, disappointed with the gift he received for giving his son's blood to save Burns' life. Smithers calls the hit off. When Burns finds out, he literally calls Smithers "Judas!"
- Teen Titans. The first appearance of Red X also fits this trope. He turns out to be Robin, who was trying to get contact with Slade and find out his friends. To do so, he stole items and attacked his friends, who were unaware of what he was doing. Unfortunately, Slade sees right through him and his friends don't think he was justified in tricking them.
- The Captain from Gargoyles could be considered one of the "wrong with disastrous results" variants of this: He really wanted the gargoyles to be accepted and appreciated by the humans rather than just taken for granted in times of war and despised in times of peace. End result of his plan: Most of the gargoyles were slaughtered, and the survivors (both human and gargoyle) rightly hated him for his betrayal.