In Season 10's season finale "Drive", Pratt is involved in a road rage shooting while driving a recent patient, Elgin Gibbs, home en route to dinner with Dr. Chen. As Pratt tried to drive away from the shooter, his car was forced off a bridge and into the Chicago river, leading to Pratt sustaining serious head injuries, and Chen suffering a broken leg. Elgin died from his injuries. Their interactions became infrequent due to Chen's family problems, but Pratt went over to her house during Season 11's Christmas Eve episode when he learned she quit. Chen's father begged her to let him die so she injects him with a drug that kills him, and Pratt was aghast by this idea but ultimately supported Chen as she performed euthanasia, and then consoled her as she wept over the loss of her family. This ends his life and Pratt and Chen's relationship, since Chen returns to China to bury her father's remains and is never heard from again.