Maggie's budding romance takes flight. After a woman's shocking suicide attempt, Charles searches for answers. Asher works to diagnose a patient new to the city and appears with mysterious symptoms.
The hospital goes into lockdown mode when a man with a gun holds medical staff hostage. Goodwin is forced to make a tough decision. Dr. Rhodes begins to realize his time with his father is getting short.
Ripley and Charles treat members of a cult; Ahmad's suspension takes an unexpected toll on Marcel; Abrams' 5-month-old son lands in the E.D. under questionable circumstances.
Dr. Charles and Caroline set some major plans; Ava fights to keep her relationship with Connor. Agent Lee informs Will of news that may put his life in danger.
After a major accident at O'Hare, the E.D. is concerned one of their own is in mortal danger. Will's proposal for a safe injection site goes to the board for consideration. Natalie and Goodwin become concerned for Gwen.
The doctors and nurses of Chicago Med brace for an influx of patients when a multi-vehicle accident during a blizzard puts the hospital in scramble mode.
Choi and Halstead argue over how to treat a patient with stroke symptoms while Manning treats a boy who fell in the river and watches the family drama unfold.
An overflow of patients is rushed into Chicago Med following an apartment blaze and Rhodes tries to save a firefighter's life, while the two Halstead brothers face their own personal battle.