Memento's protagonist Leonard Shelby (Guy Pearce) is on a mission to find the man who murdered his wife. But Leonard suffers from a rare form of amnesia, so that in order to keep track of his life, he must surround himself with written reminders, some etched on his own flesh. The brilliance of Memento has had moviegoers coming back for more. James Mottram now offers the fullest imaginable guide to the film's complexities, and answers some - if not all - of the innumerable questions it provokes.