Frost (2004)

When Anita, the police commissioner's wife, is found dead and disfigured in the bathtub, Lieutenant Braque initiates an all-out manhunt to find the commissioner. But, soon it becomes apparent to investigators that nothing is as it seems. The victim's diary is full of shocking entries, including details to an unsolved hit-and-run case; an unsolved murder that seems to be at the core of this cold-hearted killer. Valerie, the surviving victim of the hit-and-run, has been distraught for the last five years, mourning the death of her sister in the "accident." Recently released from a mental institution, where she had been undergoing treatment for post-traumatic stress, she becomes the police's prime suspect in Anita's murder. But then the witness list is starting to read like the obituaries, and new evidence forces Braque to look inward, at his own department. Detective Phil Randall was there, the night of the hit-and-run. He thought he had tied up all the loose ends protecting him and Anita, and now it seems to all be unraveling. Lieutenant Braque is asking too many questions. Questions Phil doesn't have all the answers to. After his alibi falls victim to the Phantom Killer, he has to find Valerie to end the suspicions. Lieutenant Braque finds himself on a race to solve the case before Phil can get to his next victim. The chase leads Valerie and Phil into an underground bunker with no way out. Stuck in there, face to face, two killers find out the truth about each other. Who will survive? And who is the real Phantom Killer?