Flashback: A scene that interrupts the present action of a narrative work to depict some earlier event — often one that occurred before the opening scene — via reverie, dream, remembrance, or some other mechanism. The term may be used to refer to the scene itself or to its presentation.
Flashback is a form of analepsis, one of the three major types of anachrony. The device has its origins in the ancient epic tradition of beginning a work in medias res (“in the middle of things”) and then moving back in time to tell the beginning of the story.
EXAMPLES: In The Naked and the Dead (1948), a novel of World War II that depends upon the interplay between past and present, author Norman Mailer identified flashback sequences via the indented, boldfaced phrase “The Time Machine.” Section Two of Anthony Doerr’s novel All the Light We Cannot See (2014) bears the date “8 August 1944,” whereas Section Three takes the reader back to “June 1940.” Movies with flashbacks include Casablanca (1942), in which the song “As Time Goes By” signals a flashback to Rick and Ilsa’s whirlwind romance prior to the Nazi occupation of Paris, and The Accused (1988), which flashes back to the scene of a gang-rape near the end of the movie, as a witness is testifying at trial. The television show Lost (2004—10), in which victims of a plane crash struggle to survive under mysterious and threatening conditions on a tropical island, incorporates multiple flashbacks in nearly every episode to provide characters’ backstories and shed light on their motivations, secrets, and pre-crash connections with others on the island.