Hooten's mentor, Dr. Arvin Wayne (guest star Hal Holbrook), walks into the wrong procedure on the wrong day, leading the surgeons at Chelsea General to question the cognitive abilities of one of the hospital's elder statesmen. When a top competitive swimmer suffers a seizure in the emergency room, Villanueva follows his gut - leading to a surprising diagnosis. Tina must perform a risky transvenous thrombolysis with Ty and Michelle's help. And Sydney implies that Lieberman (guest star Jonathan Silverman) might be a crummy doctor for missing the signs of bacterial endocarditis in a former patient.