All the conspirators save only he
Did that they did in envy of great Caesar.
He only in a general honest thought
And common good to all, made one of them."
So, you have a group of people — whether it be a group of friends, a military, government system, a church, or something else — that are supposedly all united by a common belief, cause, or goal. It's been loudly proclaimed, everyone knows who they are and what they stand for...
And none of them really believe it.
Whether out of corruption, ambition, greed, or some other reason, all of the people who claim to be part of this group don't really care about the cause and mostly care about themselves... Except for one person, who truly and honestly believes in the cause, and is increasingly shocked or appalled when he sees that everyone else is a hypocrite.
If he had a mentor who taught him these ideals, or he idolized the organization as a whole, realizing what the group is really like will often result in a Broken Pedestal. This often is the prelude to a Defector from Decadence, if he switches sides in his disillusionment, or The Paragon Always Rebels, if he goes to make his own side to do what the group should have been doing.
Contrast Not in This for Your Revolution, which may come from a single non believer with pragmatic motives among a group of believers. See also Took the Bad Film Seriously, which is about the one actor in a bad movie who doesn't realize/care it's bad. Compare Flock of Wolves.
- Attack on Titan
- Most people who seek to join the Military Police do so because of the perceived life of ease and luxury, which is sure to be far, far away from man eating Titans which supposedly have humanity dangerously close to extinction. From the 104th Trainee Corps, only Marco actually believes in the honor of serving the King, everyone else trying to join the Military Police just want the easy life.
- And we later encounter another character in the Military Police with similar idealistic beliefs. Marlowe declares that his goal is to work his way up the chain, purge the now notoriously corrupt Military Police of corruption and turn it back into a force humanity can be proud of. His fellow new recruits mock him for his attitude and think his goal is stupid. When he sees some of his superiors selling arms to the black market, he tries to stop this, it goes about as well as you'd expect.
- Flashbacks reveal that Reiner Braun was this among the Warriors. While the others privately expressed misgivings about their duty, and went along with it out of a sense of obligation or self-professed weakness, he genuinely believed every word of the lies their superiors told them. His desperate attachment to these lies continued to the point of lashing out at his comrades, and eventually drove him insane from guilt. Even after accepting that everything was a lie, he remains loyal simply because he doesn't believe there's any other options left for him.
- The French comic Leo Loden has an animal rights group called NOE with a Granola Girl secretary. It's actually a front for a far-right organization with the same initials, with the secretary being the only one unaware of its true nature.
- A Gahan Wilson comic that shows two rather elaborately dressed priests busy doing some kind of religious ritual in front of an idol implies this about the priest in front (who's busy shaking some kind of totem or fetish at the idol) as his eyes bug out in surprise when the priest behind him (who's busy tapping a little brass gong) asks him "Do you really believe in any of this stuff?"
- In IDW's The Transformers: Robots in Disguise, the Decepticons started out as an equality movement that got twisted into fascism and war-mongering. Only a few seem to still be committed to the early ideology as opposed to the opportunity to indulge in sadistic violence, the most notable being Soundwave.
- In Atlantis: The Lost Empire, Milo is the only character who thinks the expedition's goal is to find Atlantis to advance science, it turns out the entire expedition is Only in It for the Money. He does manage to make most of the team switch sides once they find out that taking the treasure will mean destroying the Atlantean civilization, barring the main bad guy and his right-hand woman... and their Gas Mask Mook army.
- In Equilibrium, a dystopian society uses Emotion Suppression drugs to prevent violence, strife, and dissension from breaking out, and main character Preston is an enforcer for the regime. Eventually, Preston goes off the drugs and joins the rebels, and while singlehandedly infiltrating and shooting his way to the dictator, he finds that nobody in the higher echelons is really on the drugs; one of the biggest advantages to a totalitarian regime of suppressing peoples' emotions is that they can't recognize a subtle 'sense-offender' unless their leaders explicitly tell them what signs to look for, and throughout the film we get subtle clues that there is some serious psychotic emotion surging through the regime that has gone unnoticed; Brandt constantly smirks and asks questions that would not exist without curiosity (and his shouting at the 3/4ths mark outs him as an emotional glory-hog, which he papers over by focusing his tirades on arresting Preston), DuPont shows a level of pride in his work and in the supposed superiority of his preferred fighting style (which gets applied in the climax), rank-and-file military are demanding instead of stoic and raise their voices in combat (one the dictator's elite guard actually snarls), methods of execution involve burning people alive instead of shooting them and saving resources, etc.
- Near the end of the Street Fighter movie, we find that Dumb Muscle Zangief is the only one who believed Bison's lies and propaganda about his cause. Everyone else was just there to get paid.
- In Pirates of the Caribbean: At World's End, when Captain Jack learns that yet another of his rescuers had an ulterior motive, he calls for a show of hands by anyone who'd come to save him just because they missed him. Only a few people raise their hands, and in the trailer only the monkey does.
- The Hunt for Red October: Dr. Petrov is the only officer serving on the "Red October" (other than The Political Officer, and Ramius kills him soon after leaving shore) that doesn't believe that the Soviet Union and Communism are a load of bull, (all of the rest are loyal to Captain Ramius and had been tossed to the wolves by the Party in one way or another) and as a result he's left in the dark about the plan to defect and turn the submarine over to the Americans. When the time comes to fake scuttling the ship so it "won't be captured", he's convinced to leave the ship with the rest of the crew while the other officers stay and he sincerely swears to Captain Ramius that he will try to make sure the Captain gets the Order of Lenin for his (alleged) Heroic Sacrifice.
- In The Man Who Was Thursday, while the rest of the anarchists in the club are police spies spying on each other, the character Gregory is an actual anarchist, and is not pleased at the reveal.
- Similar to the above, in the backstory of the novel Beach Music by Pat Conroy, during college Shyla became passionately involved in an anti-Vietnam War movement. While presumably there are other sincere people that we never actually encounter, both the leader of the movement and Shyla's lover turn out to be moles, a betrayal that is not good at all for a Broken Bird with some schizoid issues.
- Monstrous Regiment takes place in a country where the common people have more or less given up the faith in their petty and increasingly unhinged god and begun transferring all the belief and feelings toward the country's Duchess. While all the humans in the squad pay lip service to the Duchess, (except one girl who hates everything the Duchess and the country's mainstream society stands for), Wazzer is the only one who truly believes in her. Because Discworld gods are powered by belief, all this has turned the Duchess into a quasi-deity and makes Wazzer into a Joan Of Archetype who hears the Duchess' voice guiding her.
- Night Watch: In the revolution to overthrow Lord Winder as Patrician of Ankh-Morpork, Reg Shoe is the only one who really thinks that a revolution will actually be a good thing or change anything. When he finally realizes just how little anyone cares about his ideals, the cynical, self-interested way that people are using the revolt for career advancement and such, and that the revolution is going to be a Full-Circle Revolution, he breaks down sobbing. And then he stands up and starts fighting again.
- In Small Gods, the "great god" Om is stunned to realize that despite having a theocratic, fundamentalist church devoted to him and a nation of millions named after him, nobody actually believes in him. (Again, this in a world where Gods Need Prayer Badly.) People believe in the Church, sure, and have feelings about Om such as hope and fear, but the only one who actually believes in Om is Brutha, who ranks so low in the Church hierarchy that he's barely even considered a part of it. There's also one extremely determined atheist that militantly and very specifically disbelieves in Om even while acknowledging the existence of other gods. Om notes that this kind of attitude is so similar to actual belief that it's almost as good as the real thing.
- In A Song of Ice and Fire, two characters with something of a Duality Motif come to represent this trope:
- Jon Snow joins the Night's Watch believing the hype about a thin line of defense against the supernatural horrors beyond The Wall, but he's dismayed to find that over the centuries they've become an Army of Thieves and Whores who don't believe in the Others and see their duty as preventing raids by the thoroughly human wildlings. The few other people who believe in the Watch having a higher calling are either unaffiliated (Melisandre), die off over the course of the story, or are sent away to raise support elsewhere. Jon's lack of support on this issue is Deconstructed: though he rises up to Lord Commander, his efforts to ally with the hated wildlings cause a huge amount of dissent and he's assassinated by mutineers.
- Jaime Lannister starts off as a cynical Blood Knight In Sour Armor widely reviled as a regicide and an oathbreaker. He was only accepted into the ranks of the Kingsguard to spite his father (as Kingsguard cannot inherit titles), and nowadays he only sees it as a way to be close to his sister/lover the Queen. However, after a long arc of Break the Haughty and a positive knightly role model in Brienne of Tarth, Jaime starts to think about restoring his own honor and that of the Order he has come to command — however, by this point his subordinates are mostly thugs and lackeys, a world away from the Knight in Shining Armor stories that inspired a young Jaime to join in the first place.
- In M*A*S*H, Frank Burns and Margaret Houlihan are the only main characters who actually believe in the cause of The Korean War. All the other main characters are draftees who share the writers' anti-war views.
- In the third season of Blake's 7, Cally is left as the only genuine idealist in a group of revolutionaries, most of whom were originally criminals who happened to break out of jail with an imprisoned revolutionary leader. After her death at the end of the third season, the fourth season leaves the regular cast with no-one who actually believes in the cause politically, with the survivors fighting only for self-preservation or to satisfy their own psychological issues.
- Farscape, which was blatantly influenced by Blake's 7, had only one character who was actually fighting the Peacekeepers for idealistic reasons, and she died early in the third season. It's lampshaded in one episode where Rygel "nobly" offers to escape alone from a lethal situation so that he can carry the team's message into the future, and another character points out that they don't actually have a message.
- Played for tragedy on one episode of CSI: A con man had set up a cult that ripped off the "Heaven's Gate" cult in Nevada, a scam that he had done repeatedly (brainwash people, take all their possessions, do a faux-suicide with Kool Aid and sleeping pills, run away while everybody's knocked out. It is said that he had not been caught because the other times he'd done that had not been fully documented out of the cultists' embarrassment). While the other cultists "believed" out of brainwashing, one young woman truly believed because her life was crap and she wanted to go someplace better, and when she discovered the con man checking his getaway vehicle and he let her into the secret of his scam, she killed him and went out to get real poison for the mass suicide (and while she chickened out of committing it with the rest of the cultists because she was horrified at seeing their death throes, she tried to kill herself anyway a few hours later. The cops caught her and saved her life, but Brass made it clear in the aftermath that someone believing this kind of stuff as hard as she did probably won't be deprogrammed any time soon).
- Paranoia occasionally has a citizen who actually believes The Computer is doing the right thing (not just playing along to serve their own ends, or drugged/brainwashed into it).
- As seen in the quote on top, this is the most common interpretation of Brutus in Shakespeare's play Julius Caesar. All the other conspirators who convinced Brutus to join them by decrying Caesar gaining the power of a king mostly just wanted that same power themselves. Brutus on the other hand was horrified by the thought of a king taking over the Roman Republic. This is why Brutus gets treated sympathetically by Anthony and Octavian after his death.
- In Pokémon Black and White, N is the only important member of the Animal Wrongs Group Team Plasma who actually believes in liberating Pokemon. Worse, he's being manipulated as a puppet figurehead. Pokémon Black 2 and White 2 reveals that roughly half of Team Plasma actually did believe in helping Pokemon, and after the events of the first game they split off from the main team and do what they can to atone for the group's misdeeds.
- In Call of Juarez: Bound in Blood, the Token Good Teammate William very quickly becomes the only one among the three McCall brothers to still believe in using the Juarez treasure to rebuild their homestead and return to a peaceful family life, as Thomas and Ray's motivations rapidly decay into just grabbing the money and running for it.
- Metal Gear Rising: Revengeance has Senator Armstrong, with this heavily prominent in his Motive Rant about USA being a worse version of Eagleland while going No-Holds-Barred Beatdown on Raiden.
- In Armored Core For Answer, the Player Character is this on ORCA's path, as the rest of ORCA is either killed in action, or in Thermidor's case, was a Mole in Charge for the corporations the whole time. By the time the last mission happens, the player is the only one who still holds to ORCA's original plan to free humanity to go to space, and the one who ultimately carries it out.
- Late in Exo Squad, a group of Neomegas conspire to kill Big Bad Phaeton, whose Villainous Breakdown is likely to lose them the war against Terrans. They convince Marsala (a Neo Sapien serving in the Terran Exo Fleet) to cooperate by saying they need him to capture Phaeton, so they can make peace with humanity. In actuality, they just want to take over the Neosapien race(s) and are quite willing to turn around and finish wiping out humanity afterward. Only one of the Neomegas, Galba, actually believes in the stated goal. Ironically enough, that saves Galba's life when the coup fails, as an aide loyal to Phaeton hears the other Neomegas order Galba's arrest when they think their plan has succeeded, so the aide and Phaeton both conclude that Galba must have been loyal to Phaeton, and the other Neomegas were turning on him due to that.
- While he's not the only true believer, the cult leader in the Chip 'n Dale Rescue Rangers episode "The Cola Cult" was certainly the only one in the cult's priesthood who genuinely believed his religious order was intended to enlighten its various adherents. He's genuinely surprised and dismayed to discover that the rest of his colleagues have been stashing the worldly possessions new converts surrendered to the cult in a kind of treasury, and are exploiting the cult's followers. He also does what he can to help the Rangers escape and overthrow the priesthood, and is implied to be willing to try implementing their suggestion at the end that the cult's former laity continue to meet as friends (and maybe set up a social club) rather than as cultists.
- Played for laughs in an episode of Teen Titans. Brother Blood, headmaster of the HIVE Academy, discovers his two top students are actually good guy Moles. In frustration he angrily asks "Was anyone in my school actually here to learn?!"
- Recess: In the episode, "The Great Can Drive", 3rd Street School holds it annual Thanksgiving Canned Food Drive to help the homeless, the poor, the handicapped, etc. Initially most of Miss Grotke's class, save for Mikey, bow out of the drive, knowing whichever class has the Ashleys is going to win. When the Ashley's start taunting Mikey over collecting cans by himself, however, T.J. rallies the rest of the class to help Mikey... purely in order to beat the Ashleys. Mikey remains the only one involved for the sake of helping the less fortunate.
- Common in Real Life fraudulent charities that exist purely to con softhearted donors out of their money. Con artists who set them up will often recruit at least one person who doesn't know it's a scam. These people can be great at collecting donations, as they truly believe those donations will help people, and people who wouldn't otherwise donate can sometimes be convinced to do so simply due to the sincerity of these believers. The con artists also frequently attempt to use these believers as the Fall Guy, ensuring that all of the "charity's" paperwork incriminates the true believer and not them.
- The same goes for fake religions (none of which will be named here): even when a cult's founders are just looking for easy marks to exploit, they'll often promote some of their early converts to the leadership, because nothing sells a religion quite so convincingly as a true believer. The difference is that since these scammers are often playing a Long Game, these true believers usually will not be set up as patsies for anything, and can sometimes linger on and keep the cult going even when the original founders are long gone.