The phrase "slumming it" was invented for movies like Before I Go to Sleep. Starring Oscar-winners Nicole Kidman and Colin Firth, as well as Mark Strong, this is a thriller that is free of personality, invention, and, well, thrills. Dumped unceremoniously into a Halloween release, it's the kind of film that only people who have no parties to go to and no kids to chaperone will see. Even if you don't have "psychogenic amnesia," the faux-disorder from which the protagonist suffers, you will forget about this movie almost immediately.

Christine (Kidman) can't remember anything that happens between when she wakes up and when she goes back to sleep, which causes her to wake up every morning thinking the man sleeping next to her is a stranger. Also, she still thinks she's in her mid-twenties, when she's actually forty. Her husband, Ben (Firth), is growing tired of reminding her that, yes, they are indeed married and she suffered traumatic brain injury and so on, and now she spends her days waiting around in her gloomy house until the next day so it can happen all over again. But Christine is making progress with her disorder with the help of neuro-therapist Dr. Nasch (Strong), who suggests she keeps a daily diary on a video camera so she can stay up-to-date. She can't tell her husband, though, because of… reasons. We eventually learn why, but at first it's an utter mystery why she can't say anything. He's trying his hardest, dammit!

Maybe, or maybe he's not what he seems. Or Dr. Nasch. Or Christine. Or her best friend (Anne-Marie Duff), who fell off the face of the earth for no apparent reason. Writer-director Rowan Joffe lobs red herrings at the audience like a commercial fisherman, but no amount of misleading can distract us from the truth that this movie is a complete bore. Joffe makes a token attempt at establishing a moody atmosphere by draining the color from the film, leaving only the colors of the grey spectrum, alongside plenty of cold, British rain (like, twenty monsoon seasons' worth of rain). This meager success is undone by his insistence that everyone be filmed in extreme closeup one hundred percent of the time. There's claustrophobia, and then there's lazy composition. This film falls into the latter category. In addition, jump scares—produced by Christine's bizarre tendency to wander into oncoming traffic—do not count as proper ways to establish tension, Mr. Joffe.

Only Strong comes out smelling like roses here, because he capably maintains a sense of menace even as he tries to help Kidman's character. Her trademark breathiness is fully on display here, as we get plenty scenes of her desperately whispering to her camera that she just doesn't know who to trust. Firth seems positively bored by it all, as his lines are delivered in monotone as though he's in a Bresson film. To paraphrase Ben Croshaw, the expression on Firth's face is that of detached disdain, one that neatly mirrored my own while watching this movie.