After a harrowing hostage incident left the night shift team badly shaken, everyone is finally back to business...everyone except TC Callahan, who has been temporarily suspended from the hospital after a PTSD breakdown on the job. After recovering from his near-fatal gunshot wound, Topher Zia has temporarily taken over as chief of the night shift while Jordan Alexander fields scrutiny over her medical mishandling of the man who shot him. TC can't stay away from the action however and joins Jordan out in the field, and with the help of head surgeon Scott Clemmens, they push the limits of medical technology to save a father trapped beneath an elevator. Dr. Joey Chavez brings a new zen vibe to the ER when he steps in as chief surgeon on a freak motorcycle accident case, working to the beat of his own drum. Meanwhile, Ragosa returns to the ER with a surprising new lease on life after surviving cancer.

The night shift crew is put to the test when a teenage couple and a young mom land in the emergency room after a serious car crash. Topher, TC, Jordan and Scott tend to the youngsters, who were returning from their secret wedding. As the girl's condition worsens, TC tries in vein to calm her distraught father. Jordan and Gwen tend to the other victim, a young pregnant woman whose fiancé is deployed in Afghanistan. The team hastily arranges a proxy wedding so that she can be married before delivering the baby through an emergency caesarian section. Meanwhile, Paul tends to a wealthy, eccentric hospital benefactor who teaches him it's ok to follow his heart.