A mind-controlling drug that could enslave mankind is the threat in this two-part adventure. Phelps poses as a defecting scientist to destroy the drug and its creator. Meredyth/ Mrs. Jarvis: Dina Merrill. Phelps: Peter Graves. Turek: David Sheiner. Paris: Leonard Nimoy. Borodin: Alfred Ryder. Willy: Peter Lupus. Katherine: Brooke Bundy. Barney: Greg Morris.