Dick Van Dyke as Dr. Mark Sloan, an amateur sleuth now investigating a mysterious death in the OR. Van Dyke's son Barry is recast as the doctor's son, a police detective. Dr. Rachel Walters: Suzanne Pleshette. Marilyn Cabot: Christina Pickles. Dennis Chapin: Ben Masters. Amanda Bentley: Cynthia Gibb. Dr. Jack Parker: Stephen Caffrey.