Quite frankly, the most important element of any thriller is that it be thrilling. And Before I Go to Sleep, written and directed by Rowan Joffe and based on the extremely popular book by S.J. Watson is in this sense successful, as the movie thrills.

The less information divulged about the plot of Before I Go to Sleep, the better. The lead character of Christine wakes up every day and has forgotten her memory. Thinking of a more serious 50 First Dates puts us on the right track. Christine, played by Nicole Kidman is a role that seems to fit her icy persona perfectly, this film and Stoker as well as her early thriller Malice seems to represent a comfortable space for Kidman,

The film sees Christine married to Ben (Colin Firth), but she does not remember being married to him, and Ben has artfully arranged photographs and mementos which remind Christine whom she is, and why she should trust him. Like in The Railway Man, also a literary adaptation, Kidman and Firth make a charming pair. However, Christine’s memory issues cloud their partnership, and it certainly does not help that Christine has been meeting with a Dr. Nasch (the always welcome Mark Strong), and may be coming close to recovering new memories.

Once the particulars become familiar, the film develops the rhythm and pacing of a thriller, and the brisk running time, and twisty plot allow for a compelling watch, as the film is essentially a three-hander, which makes it extremely helpful that the three hands are all fairly capable jugglers, Kidman especially, as it she is by now believable as English. The film hits the correct beats of a thriller, though at times that beats seem a little discordant. Before I Go to Sleep develops its natural rhythm of moving from one revelation to the next, and though this element of surprise will play better with those unfamiliar with the source material, there is a lot here to entertain and surprise.
There are some slightly incongruous elements, and the last ten minutes or so cannot fulfill the promise of the early film, veering into sappiness that seems at odds with the remainder of Before I Go to Sleep. But the movie should keep audience members awake long after the surprising reveal, and make for some sleepless nights.

[star v=3]