S3, E12: Featuring Special Guest Star Michael J. Fox; with the arrival of a visiting Super Doc to the hospital, J.D. reevaluates his mentor. -- Dr. Kevin Casey (guest star Michael J. Fox) comes to Sacred Heart as a visiting medical doctor and an accomplished surgeon despite being diagnosed with a severe case of obsessive compulsive disorder. Dr. Casey touches everyone at Sacred Heart in a special way during his visit, beating his old resident buddy Dr. Cox at his own game of wits, leaving Turk in the dust with his surgery time and teaching J.D. some very valuable lessons about learning to believe in himself. Meanwhile, Dr. Kelso strikes a deal with the Janitor to take care of the hospital's garbage, only to find himself eyeballs deep in it.