Robert Young plays Dr. Marcus Welby, a dedicated family physician who made house calls a priority in life. From week to week Welby was tasked with some of the most devastating disorders and serious situations an M.D. can face, but confronted them with a fierce honesty and dedicated compassion that made him a virtual superhero with a stethoscope. But he couldn't do it alone. Enter Dr. Steven Kiley, portrayed by the strapping and very new James Brolin in his first regular television role.