Samantha Caine (Geena Davis), a suburban school teacher, suffers from amnesia. When her mysterious past begins to haunt her idyllic life, she sets out on a desperate search to discover her true identity.
Aided by Mitch Hennessey (Samuel L. Jackson), a dead-beat private detective, she follows a trail of clues into the middle of a terrorist conspiracy in the US Intelligence community. Repressed from her memory is her former life as Charly Baltimore, a highly trained secret agent and killer. But Charly is slowly re-emerging, which spells trouble for the terrorists and anybody else who gets in her way...