Part IV (Season 2)

"Part IV" is the fourth episode of the second season of The Sinner. It is the twelfth episode of the series overall. It premiered on August 22, 2018. It was written by Jesse McKeown and directed by Jody Lee Lipes.

Synopsis
A psychiatric patient's story sends Heather on a hunt for Marin. Ambrose visits Vera at Mosswood and gets a taste of the group's intense "work."

Cast

 * Bill Pullman as Detective Harry Ambrose
 * Carrie Coon as Vera Walker
 * Natalie Paul as Detective Heather Novack
 * Hannah Gross as Marin Calhoun
 * Elisha Henig as Julian Walker
 * Tracy Letts as Jack Novack