Colin Firth is set to star with Nicole Kidman in helmer-scribe Rowan Joffe’s thriller “Before I Go to Sleep” for Scott Free and Millennium Films.Firth will play Kidman’s husband in the film, which also stars Mark Strong and Anne-Marie Duff. Based on British author S.J. Watson’s book of the same name, pic follows a woman with amnesia who wakes every day with no knowledge of who she is and must reconstruct her memories from a journal she keeps. As terrifying new truths emerge she is forced to question everyone around her. “Sleep” will lense at London’s Twickenham Studios, and at locations in and around London, at the end of the month. Producers include Liza Marshall, Ridley Scott and Mark Gill. The film was developed with StudioCanal, who will release in Blighty. Millennium/Nu Image handles worldwide sales. Firth and Kidman recently teamed in Jonathan Teplitzky’s “The Railway Man,” which is currently in post and due for release this year.