Rachel Watson, devastated by her recent divorce, spends her daily commute fantasizing about the seemingly perfect couple who live in a house that her train passes every day, until one morning she sees something shocking happen there and becomes entangled in the mystery that unfolds.
A traumatised veteran, unafraid of violence, tracks down missing girls for a living. When a job spins out of control, Joe's nightmares overtake him as a conspiracy is uncovered leading to what may be his death trip or his awakening.
Though Kevin has evidenced 23 personalities to his trusted psychiatrist, Dr. Fletcher, there remains one still submerged who is set to materialize and dominate all the others. Compelled to abduct three teenage girls led by the willful, observant Casey, Kevin reaches a war for survival among all of those contained within him — as well as everyone around him — as the walls between his compartments shatter apart.