In "The Sixth Sense," the shocking twist is the revelation that the main character, Dr. Malcolm Crowe, is a ghost. Throughout the film, he tries to help a young boy, Cole Sear, who can see ghosts. However, at the end of the film, we discover that Dr. Crowe is dead, and he doesn't know that he's a ghost. The scene where the twist is revealed is when Cole sees Dr. Crowe in the mirror, and says, "You can't see me." This is the moment when Dr. Crowe realizes that he is dead, and that he can't see ghosts because he is one himself.