Christine's husband Ben (Colin Firth) seems at first to have the patience of a saint. Each morning, he explains to Christine who she is, who he is and when they got married. He shows her a wall of photos and tells her where she can find everything. A few weeks earlier, and unbeknownst to Ben, Christine has started seeing a neurologist, Dr Nash (Mark Strong), who is trying to help her recover some of her short-term memory. He gives her a video camera and tells her to record messages to herself each time she manages to claw back a glimpse into her past, and then he calls her each morning to remind her to check out the camera so that she doesn't have to start from square one.
Christine starts to discover that Ben is hiding things from her. Why doesn't he want to talk about her accident, for instance, or about her friend Claire (Anne-Marie Duff)? Of course, the trouble is that Christine doesn't know if he really is keeping secrets for malicious reasons or because he can't face the pain — both his own and Christine's — of telling the same traumatic stories from scratch time and time again. In many ways, the audience is in a similar position: a lot of the time, we have no idea whether or not Ben is telling the truth.
Before I Go to Sleep is tightly edited, clocking in at just over 90 minutes, and it will keep you on the edge of your seat throughout, thanks to an ever-present, unsettling tension. In fact, some of the more excitable members of the audience at the preview screening I attended last night had trouble staying on their seat during some of the more violent moments. And there are a fair few shocks and violent moments, and enough twists and turns to keep those who haven't read the book guessing.
These things all make Before I Go to Sleep a decent, watchable thriller, but the performances elevate it into something more interesting. I don't always like Kidman's characters, but I think she was a good casting choice on this occasion. Christine is a role she often plays — the highly strung, fragile femme who is forced to draw on an inner strength she never knew she had. Firth, meanwhile, is getting very good at playing creepy, and it's impressive how his Ben switches from devastated, devoted husband to something that, in Christine's eyes, is highly sinister. Strong doesn't get as much screen time, but he's a nice contrast to Firth's character as the good doctor — or is he?