SPOILER ALERT: Former 'Grey's Anatomy' cast member makes special appearance on season 17 premiere
SPOILER ALERT: Former 'Grey's Anatomy' cast member makes special appearance on season 17 premiere

Dr. Derek 'McDreamy' Shepherd, who Patrick Dempsey played for more than 10 seasons, is back for at least part of Season 17 of ABC’s 'Grey’s Anatomy.'