Colin Firth wears an Omega Speedmaster

Rowan Joffe's Before I Go to Sleep (2014), adapted from S.J. Watson's novel, hands Nicole Kidman a cruel premise: Christine Lucas wakes every morning remembering nothing, her memory wiped clean overnight by an old head injury, so each day has to be explained to her from scratch. A man tells her he is her husband Ben and walks her back through their life. A neuropsychologist, Mark Strong's Dr. Nasch, contacts her in secret and has her keep a video diary so the days can begin to connect.

The man is lying. By the end, the husband Ben turns out to be Mike, a man Christine was once involved with, who attacked her when she would not leave her marriage and has spent the years since keeping her, feeding her a false past one morning at a time. Her real husband, the actual Ben Lucas, is alive and elsewhere, along with the son she was told had died. Firth plays both registers at once, the patient caretaker on the surface and the man with something clamped down underneath.

The watch is easy to miss, which is part of why it is interesting. There is exactly one good look at it, around twenty-five minutes in, when Ben holds Christine in the rain and his wrist turns to the camera: an Omega Speedmaster Professional, the moon chronograph, on a dark strap. It does not appear before or after. It may well have been Firth's own watch rather than a costume choice, there for a single scene and then gone, which gives it an odd resonance in a story about a man who is not who he claims to be. The one thing on his wrist we can actually identify may not be his character's at all.