Eric C. Lynch

Doctors Manning and Rhodes suspect that two separate cases involving sick babies may be connected. A homeless patient's upbeat disposition enlightens Doctors Halstead and Charles, and Dr Choi and a Navy corpsman deal with the toll of gang violence.

Severide tries to prove his suspicions about the arsonist's identity, Casey gets accustomed to his new lifestyle, and Dawson goes on a date with a regular from the bar.

Tennant's team, along with NCIS agents Nick Torres and Jessica Knight, tracks The Raven's whereabouts to the island of Oahu and learns about his plans to attack the world's largest international maritime warfare exercise.