Halstead returns to Med to help Goodwin with a secret investigation; Archer and Charles deal with twins who insist on being identical inside and out; Stevie and Dylan treat a young patient with sickle cell anemia.
Dr. Marcus Andrews enlists the help of Dr. Neil Melendez to perform a very sensitive kidney transplant between a pair of twins; Dr. Shaun Murphy decides to take an impromptu trip with his friend Lea and leave his problems behind.
Complications force the team to make a life-changing decision regarding the twins; following his trip with Lea, Dr. Shaun Murphy decides he needs a more permanent change.