J.D. and Turk move patients from the remodeled geriatric wing and some escape, wandering aimlessly around Sacred Heart. Carla and Elliot try to get staff support for Dr. Kelso but no one is willing to speak out. Mr. McRae, a patient of Dr Cox's for the past two years, is back with his mystery illness. J.D. and Turk tell Ted that Kelso is being forced out and in celebration of his impending freedom from his boss, Ted runs naked from the hospital and gets knocked over by Janitor's van.
Kelso takes a quiet moment outside by the wall of remembrance with student nurse Boon, while Elliot and Carla stitch up Ted's tongue. Elliot and Carla can't figure out why no one will support Kelso when deep down they know everyone loves him. Ted tries to argue to the contrary, but he can't speak. Jordan suggests Carla and Elliot confront the Board at the meeting that evening. Janitor also offers his help, as he can control people's minds with magic.
J.D. and Turk extend an olive branch to Cox after earlier trying to bait him about his lack of diagnosis. He gives them Mr. McRae's sample that needs to be taken to the lab for tests. Kelso still has Boon trapped outside listening to his rambling memoirs of forty years of medicine, while pensioners meander unattended around the hospital grounds. Elloit and Carla ask Cox to help them confront the Board, but Cox admits he can't wait to get rid of Kelso. Cox then asks J.D. and Turk about the sample they delivered for him to the lab. J.D. and Turk realize they've misplaced it and retrace their steps until they locate it sitting on a ledge in the sunlight. Remarkably, it has turned purple.
J.D. Googles "purple pee" and learns it's a symptom of a rare genetic disorder, of which Mr. McRae has all the listed symptoms. They've solved the two-year riddle. Back in the cafeteria, Elliot and Carla again confront Cox but he isn't interested in helping. When J.D. and Turk tell him of their discovery, he can't believe they found the answer to the mystery illness.
Jordan says there's no way anyone will be able to sway Cox but J.D. has an idea. He tells Cox about leaving the sample in the sun and finding the answer on Google. Cox still won't budge on the vote for Kelso through, who is still telling stories outside. Cox and J.D. tell Mr. McRae they know the name of his condition, but there is no cure. He seems happy just to know the name of it and Cox has an epiphany: It's better the enemy you know...
Carla, Elliot, Turk, Janitor and Jordan wait outside the boardroom when J.D. arrives with Cox and a group of doctors to show their support for Kelso. The Board asks Dr. Kelso to stay on in front of everyone but now having thoughts about it, and things being on his terms again, Kelso quits and walks out. The staff wonder aloud if he ever cared about the hospital. Boon assures them he did.