Martin Odum (Sean Bean) is a man with a secret. Many secrets, actually, in the form of Legends, the identities he takes on to investigate FBI cases. His supervisors think he's the most naturally gifted agent they've ever seen; his colleagues, particularly operations specialist Crystal (Ali Larter), think he's reckless, too intense, and maybe even dangerous. His ex-wife, Sonya (Amber Valetta), doesn't appreciate Martin's habit of dropping in and out of his son's life whenever he's between cases. But, scariest of all, Martin's come to suspect that his life may be a puzzle within a puzzle -- the one identity he thinks of as rock-solid just another legend.