When a sick boy is brought in, Ethan is faced with a tough decision that quickly escalates into a complicated and dangerous situation. Connor and Maggie are put to the test, while Natalie and Ethan aren't sure what to make of Elsa, the new third year medical student.
The doctors and nurses of Chicago Med find themselves on high alert when an overflow of patients are rushed into the doors following a terrifying apartment complex blaze. Dr. Rhodes fights to save the life of one of Chicago Fire's own, while Dr. Halstead and his brother Jay struggle with their own personal battle.
The crossover starts on Chicago Fire S07E02 Going to War (I). It continues on Chicago P.D. S06E02 Endings (III).
Bekker takes drastic action to keep Rhodes from leaving Med for good. Meanwhile, Halstead questions Manning's feelings about their upcoming wedding, Ethan receives shocking news about his sister, and Dr. Charles mourns a loss.
Dr. Rhodes second guesses removing himself from the team working to separate conjoined twins; Dr. Choi and April make a startling discovery about his sister; Dr. Charles uncovers troubling information concerning Dr. Reese's father.
Dr. Manning rushes to save a young boy with a life-threatening case of the flu; April suspects Dr. Choi's sister stole opioid pain killers; Dr. Rhodes and Dr. Bekker disagree over the best treatment for a cardiac patient who is 21 weeks pregnant.
After a shooting occurs during a block party, the staff is overrun with victims; Dr. Choi devises a new mass casualty plan; Dr. Manning struggles to stay focused when she realizes her son and nanny might have been at the scene.
After a 10-year-old boy is admitted to the hospital, Dr. Manning and Dr. Halstead disagree on how to best handle the boy's parents. Dr. Rhodes rushes to fix a heart that will be given to Dr. Reese's estranged father.
After taking the lead on a surgery, Dr. Bekker feels the heat after something goes wrong. Dr. Manning and Dr. Charles are faced with a tough decision concerning the gender of a 9-year-old girl. April and Dr. Reese rush to find the son of a dying patient. Goodwin's godson is admitted to the hospital.
Dr. Charles and Dr. Reese search for answers when a mother brings in her daughter claiming she is possessed. Dr. Rhodes and Dr. Bekker are tasked with finding a way to save a pair of conjoined twins. Dr. Halstead struggles to get Dr. Manning's attention. Maggie measures her options in the wake of her recent actions.
After a baby is abducted from Med, Goodwin enlists the help of Dr. Charles and Dr. Reese to find the suspect. Due to the lockdown, Dr. Rhodes must figure out a way to get into the operating room to help perform open-heart surgery. Dr. Manning and Dr. Halstead disagree on the right treatment for a patient.
