“A remarkable psychological-puzzle film, a crime conundrum that explores the narrative possibilities of noir, Memento turns its detective hero Leonard Shelby into a surrogate for the spectator, its backward narrative logic forcing us to embark on the kind of investigative work Shelby is engaged in. Shelby-played utterly convincingly by Guy Pearce as a combination of dogged determination and gaping bewilderment-is a former insurance investigator who, since his wife's rape and apparent murder, suffers from a condition that makes him unable to form new memories. But despite his severely limited powers of recollection he has vowed to find his wife's killer. . . . The final scene, which seemingly completes the narrative jigsaw . . . is a stunning tease, a tantalizingly ambiguous note on which to sign off, one that scatters our sense of certainty as we rerun the events of the past two hours in our heads.”