The universe is full of evil masterminds, whose schemes seem too brilliant to defeat — until, of course, they're defeated. But often, those schemes depend on one lowly minion, and if you just took out that henchperson, the masterplan would never have gotten off the ground. Here are 10 evil schemes that depended on an underling.
1) The Joker's Escape in The Dark Knight
The Joker runs rings around Batman and the GCPD in The Dark Knight — but he doesn't do it alone. At one point, the Joker's henchman has a bomb inside him that the Joker activates with his cell phone. The ensuing explosion allows the Joker to escape. If that henchman had just been killed, no Joker escape, no ensuing chaos in Gotham. Likewise, in The Dark Knight Rises, Bane would have been stymied without that dude who gets Bruce Wayne's fingerprints from Selina Kyle.
2) The Kazon Takeover in Star Trek: Voyager, "Basics"
A Random Kazon gets picked up by Voyager dying in an escape pod. But the evil Seska has had his body chemistry altered, and he explodes in the brig, rupturing a plasma conduit and knocking out Voyager's defenses, allowing it to be taken by the Kazon and Seska. If he'd just been left to die, none of that would have happened. Along similar lines, in Star Trek: The Next Generation's "Reunion," Duras' aide in TNG's "Reunion" who likewise has a bomb implanted in him. The bomb goes off during an argument about the Klingon Right of Succession, and throws the whole succession of the Klingon Empire into chaos.
3) Massive Time-Traveling Art Fraud in Doctor Who, "City of Death"
When you watch "City of Death" for the 500th time (not that we're speaking from personal experience or anything) you start to notice just how indispensible Hermann is, despite mostly sticking to the background. He's the butler whom the Doctor loves because "he's so violent," and he plays a key role in stealing the Mona Lisa, along with the Countess. No Hermann, no discreet sales of Gutenberg Bibles. And no intimidated Russian physicist in the basement.
4) A Major Coup in the G.I. Joe Movies
In the first G.I. Joe movie, Zartan's an expert in make-up and disguise, who's just one of Destro's aides. He helps the Baroness and Storm Shadow acquire nanotech warheads. And if he'd died around this point, he'd just be a henchman who was killed. But instead he survives, the nanotech is used to alter his appearance, and he takes the place of the President, leading directly to the events of the second movie.
5) Finding the Key, in Buffy the Vampire Slayer Season 5
Jinx is like the archetypal minion — fawning, slightly incompetent, and constantly being browbeaten by his boss, the goddess Glory. And yet, Jinx is the one who seems to get stuff done around here. And Jinx is the one who finds out that Dawn is the Key, when Glory is totally stymied. If our heroes had just wiped out Jinx the first time they saw him, Dawn might have been safe a lot longer.
6) Bringing Back Voldemort in the Harry Potter books
Voldemort's return relies on at least a couple of hench-peeps, who could have been wiped off the map easily, bringing the whole thing to a finish early. Like Quirinus Quirrell in The Philosopher's Stone: We know Snape has suspected Professor Quirrell was up to no good for a lot of the book. Sometime before Halloween, at least, since he recognizes the troll attack that night as a distraction. And if Snape had killed him or even just turned him in (seriously, this is a world with truth potions. Potions that Snape has), the whole rest of the book, and Voldemort's plan never would have happened. And you could also say the same thing for Peter Pettigrew in Prisoner of Azkaban. Yes, thematically, Harry not killing him is supposed to be all about how important mercy is, but Pettigrew is super important to the Voldemort's second rise. He is, after all, the one who chops his hand off in the ceremony that brings Voldemort back.
7) Luring Bob Into a Trap, in The Incredibles
The supervillain Syndrome might be a former wannabe sidekick — but he wouldn't have gotten far without his own helper, Mirage. It's Mirage who lures Bob to come to the island and deal with the giant robot, thus setting in motion Syndrome's plan to take care of his former idol. And Bob ought to have suspected that someone named "Mirage" was not going to be what she seemed, right?
8) Starting a War in X-Men: First Class
Shaw's whole "end the human race with a nuclear holocaust" plan is sheer elegance in its simplicity — but it requires pretty heavily on Azazel, the teleporting mutant with the awesome fashion sense. He's the one who teleports Colonel Hendry to the War Room from Vegas at the start of the film. Otherwise, Hendry couldn't have advocated putting missiles in Turkey, and Shaw would still be sitting around in his awesome strip club making fancy helmets. Also, in Grant Morrison's New X-Men comics, Magneto would be totally screwed without Esme, one of the cuckoos, sneaking him his supply of Kick and keeping Magneto's powers going.
9) Launching the Yuuzhan Vong Invasion in Star Wars EU
This one's kind of a subversion. Everyone thinks Onimi is just a weak pet of the Supreme Overlord. Instead, it turns out that he's actually the force behind the Yuuzhan Vong. If only he'd been killed earlier, the war would have ended before it began. And if ships could be henchmen, then consider the Suprosa in Return of the Jedi — that's the the freighter that the Bothans and the Alliance intercepted to get at the information it was carrying. Ultimately, that information turns out to be the false information about the second Death Star that Emperor Palpatine has hinged his whole plan to eliminate the Alliance on. If, when the Rebels found that the freighter was far better armed than they suspected, they'd just blown it up, the whole Battle of Endor never would have happened.
10) Almost Every Villain Scheme in the James Bond Movies
In Goldfinger, James Bond has a lot of fun seducing Pussy Galore and turning her to his side — but he could have just killed her. Goldfinger's plan to rob Fort Knox depends on Pussy Galore's Flying Circus spraying toxic gas everywhere. No Pussy Galore, no Pussy Galore's Flying Circus, no Fort Knox break in. In Thunderball, Angelo is a SPECTRE henchman whose appearance gets altered to match that of a NATO pilot. He kills the NATO pilot and takes his place, so SPECTRE can steal the atomic bombs on his plane. If only Angelo had been killed earlier, the whole plan is off. And then there are the women who have been brainwashed to love chickens in On Her Majesty's Secret Service: they're the key to Blofeld's scheme to unleash biological warfare. Bond finds out about this, and doesn't try to capture them, kill them, rescue them, or anything else. Instead, he focuses on getting Blofeld out of Switzerland, so he can be arrested — and he fails, so Blofeld can use the women to blackmail the world. And in Tomorrow Never Dies, if Bond had just killed Henry Gupta the moment he saw him, he never would have gotten the GPS encoder to Carver, and that's the end of Carver's plan right there. And finally, the whole plot of Skyfall happens because Eve misses her shot to take out Patrice at the start of the movie — if Patrice dies, he doesn't deliver the list of undercover agents to Silva, M doesn't get pressured to resign and then nearly blown up by Silva, and so on.
Thanks to Keith Veronese, Annalee Newitz, Lauren Davis and Mary-Kate Jasper for the suggestions!