We have an exclusive Before I Go to Sleep clip to share.  Nicole Kidman stars as an amnesiac who wakes up every day with no memory.  The clip sets an ominous tone as Kidman watches a video of herself explaining her predicament that ends abruptly with a "He's coming."  Based on the S.J. Watson novel, the premise leads to darker territory as "terrifying new truths begin to emerge that make her question everything she thinks she knows about her life---as well as everyone in it, including her doctor (Mark Strong) and even her husband (Colin Firth)."

The thriller, directed by Rowan Joffe (Brighton Rock), opens October 31.  Watch the Before I Go to Sleep clip after the jump.

Official synopsis:

A taut thriller based on the worldwide best-selling novel by S.J. Watson, BEFORE I GO TO SLEEP is the story of a woman (Nicole Kidman) who wakes up every day with no memory as the result of a traumatic accident in her past. One day, terrifying new truths begin to emerge that make her question everything she thinks she knows about her life - as well as everyone in it, including her doctor (Mark Strong) and even her husband (Colin Firth).