Michael Caine wears an unidentified watch

In a study lined with chalkboard sketches and stacked papers, Michael Caine's Professor Stephen Miles sits with his hands folded on the desk, and a watch slips from under the cuff of his tweed jacket. You can see that it is round, with a pale dial on a dark leather strap, and that is nearly all you can see. Miles is Cobb's old teacher and his father-in-law, the Paris architecture professor who sends Cobb to a gifted student named Ariadne, and he is on screen for only a handful of scenes in which the watch never gets more than this glancing look.

People have tried to put a name to it, but the watch does not give itself up. No watch publication or costume interview has ever named it, and on screen the dial sits too small and too dim to read a maker. What you can make out is a plain round watch on a leather strap, and no more than that. Off screen, Caine is a serious watch wearer whose signature piece is a gold Rolex Day-Date, which makes the unreadable wrist here more of a tease than a clue.

There is one good story attached to Caine in this film, and it is about the script rather than the watch. He has said the screenplay baffled him, so he asked Nolan how he was meant to tell the dreams from waking life. Nolan told him that whenever his character was in a scene, it was real. Caine is there in the final shot, beside the spinning top, which is why he has always insisted the ending is no dream.