S2, E2: Dr. Manning (Torrey DeVitto) and Dr. Rhodes (Colin Donnell) separately treat complicated cases involving sick babies, only to uncover that the two cases could actually be intertwined. Elsewhere, Dr. Halstead (Nick Gehlfuss) and Dr. Charles (Oliver Platt) treat a homeless man with an upbeat disposition who sheds some valuable insight that prompts one of the doctors to learn a thing or two along the way. Dr. Choi (Brian Tee) has a Navy corpsman follow him for the day as they deal with the toll of gang violence in the city, while Dr. Reese (Rachel DiPillo) tries to understand the delicate balance required in her new position.