Suki is a young woman confronting her destructive mental illness using "The Siamese Burn," an experimental machine designed to eliminate multiple personalities. The closer Suki comes to being "cured," she's haunted by a thought... what if the last unwanted identity turns out to be her?
In a series of escalating encounters, security guard David Dunn uses his supernatural abilities to track Kevin Wendell Crumb, a disturbed man who has twenty-four personalities. Meanwhile, the shadowy presence of Elijah Price emerges as an orchestrator who holds secrets critical to both men.
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.