Matthew Rhys Perry Mason Actor, Producer Tatiana Maslany Sister Alice Actor John Lithgow Elias Birchard "E.B." Jonathan Actor Chris Chalk Paul Drake Actor Shea Whigham Pete Strickland Actor Juliet Rylance Della Street Actor Rolin Jones Producer, Writer Ron Fitzgerald Producer, Writer Robert Downey Jr. Producer Susan Downey Producer Timothy Van Patten Producer, Director