The Big Bad is dead... unfortunately before he was killed he already set his master plan into action, a plan that can proceed quite happily without him. The most common form of this is were the lead villain has already given his minions their orders and set them in place before his battle with the heroes. For instance if a terrorist leader is trying to assassinate a politician then killing that terrorist leader isn't much help in stopping the assassain already close to the politician. The heroes might have dealt with the key villain but still need to deal with the threat itself. Examples:
- In The World Is Not Enough Bond shoots Big Bad Elektra King twenty minutes before the end, but then must physically get aboard her captured submarine and stop her Dragon carrying out her plot to detonate a nuke off Istanbul.
- In Salt the mastermind behind the Russian sleeper agents dies less than halfway through but since the sleepers are already in place his death is irrelevant.
- Buffy the Vampire Slayer did this at least twice Angelus and Glory - the Big Bad was defeated but the ritual they had used to destroy the world had already activated and required additional sacrfice from the heroes to stop.
Hello, Unknown Troper. You'll need to get known to lend a hand here.