British writer/director Sean Ellis swaps humour for psychological horror in his slick yet superficial follow-up to 2005 romantic comedy Cashback. Delivering atmosphere rather than innovation, the brooding tale stars an icy Lena Headey as a London radiologist who becomes convinced she's being stalked by her doppelganger. Having glimpsed her mysterious double driving down the street and then confronted her in an off-screen encounter, the traumatised 30-something crashes her car and winds up in an amnesiac state. Slow-drip dread replaces genuine scares, as former photographer Ellis interweaves his own highly stylised vision with a reverential plundering of the work of genre masters from Hitchcock to early Polanski. The languid pacing enhances the precision-crafted tension, while the fractured narrative skilfully mirrors the protagonist's mental disintegration. Ultimately though, the project's technical prowess far outweighs its content, a fact emphasised by the underdeveloped, Invasion of the Body Snatchers-type climax.

The life of a successful radiologist spirals out of control when she sees the spitting image of herself driving down a London street. While attempting to uncover who the imposter could be, she stumbles into a terrifying mystery that her family and closest friends are somehow involved in, leaving her with no one to trust.