The popular literary trope of the doppelgänger—an apparition or double of a main character—is an ideal cinematic device, raising provocative questions about the people we see on screen. It is fitting that Alfred Hitchcock’s Vertigo, in which Jimmy Stewart’s obsessed detective turns Kim Novak’s character into a double—of herself—was recently named the greatest of all films. Other directors, including Luis Buñuel, David Cronenberg, Brian De Palma, Maya Deren, David Lynch, and more, have plumbed the endless depths of the doppelgänger theme. Whether we are seeing one actor play two roles, two actors playing one character, or two characters joined in what seems like a psychic connection, the films in this series use the double to explore themes of identity, performance, and the tensions between good and evil and between appearance and reality, and to show us that there is always more than meets the eye.