Before I Go To Sleep by SJ Watson is a best-selling novel among folks who, evidently, have no experience of either high-fallutin' (Christopher Nolan's Memento) or low-fallutin' (Adam Sandler in 50 First Dates) amnesiac films. The plot of the book and this new adaptation bears more than a passing resemblance to the Sandler film.

Christine (Nicole Kidman) is an English housewife suffering from anterograde amnesia, or, to use a medical term, amnesia improbabilitas. Thus, our heroine awakens every morning and is startled to discover that she is married to Ben, a frustrated chemistry teacher played by Colin Firth.

When he leaves for work, Christine is contacted daily by Dr Nash (Mark Strong), a mysterious neuroscientist who is helping her piece together memories of the brutal attack that has left her with implausible condition. Christine's condition prevents her from noting, that like many episodes of Scooby Doo, there only are two possible culprits.

Writer-director Rowan Joffe (Brighton Rock) does great work repeating the same morning scene with variations until those small differences coalesce into a thriller. Kidman plays with the otherworldly, haunted persona that has dominated much of her late career and that may or may not be a byproduct of Botox.

Strong and Firth make for perfect suspects in a crime that may or may not exist. Is one or both of them manipulating Christine for nefarious purposes? Or is she, in her delicate psychological state, seeing things that simply aren’t there? If you pop out for popcorn or a bathroom break, the spell will be broken. The script and solid performances do keep you guessing – unless, of course, you stop to think about the plot for a single nanosecond.

You couldn't say that Before I Go to Sleep isn't entertaining. But you couldn't say it was remotely plausible or logical either. Without wanting to ruin the denouement, the closing scenes depict original and sometimes unintentionally hilarious uses for common objects in a hotel room.