The plot is so involved that it requires the actors to break off from the action every few minutes to explain to each other and us just what is going on. Even so, there are holes for the picky to have a go at. And that noise? It's the desperate sound of screenwriter Tom Stoppard toiling long into the night to demonstrate that codebreaking was a) crucial b) sexy. He does it, but the film gets increasingly neurotic in the effort. Big dinner, comfy chair, Sunday afternoon, perfect.