I tried to make the title as specific as possible without being a spoiler.
In the movie,
Kahn demansKhan demands that Spock returnsreturn the torpedoes. Spock reassures KahnKhan that "Vulcans cannot lie. They are your torpedoes," and clearly omits the key detail that the bodies had been removed from the torpedoes.
Why didn't the villain, with his super intelligence, see through this, when the entire audience could?