Will 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.

Vanessa and Archer disagree on how to handle the victim of a motorcycle accident. Dylan and Charles deal with a UNICEF negotiator with repressed trauma. Stevie and Will treat a high schooler with Addison's disease and a clingy mother.

Dylan and Will deal with a dishonest patient whose lupus is in remission. A wealthy donor makes inappropriate advances toward Stevie. Vanessa, Crockett and Charles try to convince a young woman to have life-saving surgery.

Charles helps Dylan with a longtime patient who was recently diagnosed with schizophrenia. Stevie, Maggie and Vanessa investigate the legitimacy of a patient’s cancer diagnosis. Crockett is caught off-guard. Will pitches a new medical technology.

Dylan and Charles treat patients suffering from Glass Child Syndrome and misdiagnosed ADHD. Crockett has to navigate hospital politics when he cares for the daughter of a transplant surgeon. Will and Stevie must lay egos aside to help save an elderly patient.

Stevie’s personal and professional worlds collide when her mother becomes her patient. Dylan’s history with the father of a patient interferes with his perception of a case. Crockett's allegiances are challenged when his patient's liver is a potential match for one of Dr. Blake's patients.

Crockett helps Dr. Blake replace a patient’s liver. Vanessa tries to prove herself. Will continues to pursue the truth about Cooper. Ethan gets closer to returning to life in the E.D.

Dylan's loyalty to Med and the police department is challenged when an old family friend and veteran cop exhibits concerning behavior. The annual random drug testing puts a doctor’s career in jeopardy. Ethan tries a risky old-school method on a patient. Will helps Stevie search for her mother.

The outcome of Will's investigation weighs heavily on his mind as he works with Dylan to save a 4-month-old patient. Stevie and Vanessa both struggle to keep their secrets. Crockett and Blake work with Abrams to save a patient in need of a liver transplant.