According to Deadline, the pair will play alongside Harry Potter alum Jason Isaacs and The Handmaid's Tale Emmy winner Ann Dowd in the film, which takes place in the aftermath of a violent tragedy that impacts the lives of two couples in different ways.
Birney was nominated for a Tony Award in 2014 for his turn in Casa Valentina and emerged victorious in the same category two years later for his bow in The Humans.
Plimpton, last seen on Broadway in A Delicate Balance and recently in London's Sweat, earned Tony nominations for Pal Joey, Top Girls, and The Coast of Utopia, and earned an Emmy for her work on The Good Wife. Her vocal talents can be heard on the big screen this season in Frozen 2.
Kranz himself is a Broadway alum, having appeared in the most recent revivals of You Can't Take It With You and Death of a Salesman.
Production is currently underway.