analepsis

analepsis (plural ‐pses), a form of anachrony by which some of the events of a story are related at a point in the narrative after later story-events have already been recounted. Commonly referred to as retrospection or flashback, analepsis enables a storyteller to fill in background information about characters and events. A narrative that begins in medias res will include an analeptic account of events preceding the point at which the tale began. See also prolepsis.