Terry Gilliam's mind bender is actually a remake of a French short film called 'La Jetee' about a man sent back from the future to collect information about a deadly virus that wiped out most of planet Earth.
Bruce Willis plays the on the mysterious mission to uncover the genesis of the near-apocalypse. He's helped and hindered in equal measure by a doctor (Madeleine Stowe) and a mental patient (a scene stealing, Oscar nominated Brad Pitt). Expect red herrings.