The grand opening of Chicago Med's emergency department is interrupted by victims of an elevated train crash, pushing the staff to their limits.

In the aftermath of a movie theater shooting, the doctors work to treat the victims while Sharon tries to keep the press at bay.

As Doctors Rhodes and Zanetti race against the clock to save a fallen member of Firehouse 51, the case of a woman clinging to life is discovered to be similar to those of other patients.

Sharon must decide whether to put her job on the line for a patient in need.

Dr. Halstead (Nick Gehlfuss) and Sharon Goodwin (S. Epatha Merkerson) deal with a husband intent on harvesting his recently deceased wife's eggs, but soon discover some vital information that surprises everyone. Dr. Charles (Oliver Platt) is brought in by Dr. Choi (Brian Tee) to aid a patient who is trying to remove his own arm from his body because he feels like it doesn't belong. Nurse Sexton (Yaya DaCosta) befriends the father of a child who is rushed into the hospital after swallowing magnets - a situation that Dr. Rhodes (Colin Donnell) and Dr. Manning (Torrey DeVitto) are concerned could present dangerous complications. Meanwhile, Sarah Reese (Rachel DiPillo) finally learns about where she will do her residency, but has last-minute second thoughts.

Dr. Halstead and Dr. Manning deal with two warring brothers who are brought together when one finds himself in desperate need of a kidney. Dr. Reese's former patient Danny comes to a crossroad. Dr. Rhodes and Dr. Latham treat a 16-year-old girl with a genetic condition in need of surgery, but whose overprotective mother disagrees with that course of action. A convict with unusual intentions puts himself in the hospital and Dr. Charles meddles in his daughter Robyn's personal life, much to her dismay. Meanwhile, Dr. Halstead and April make a discovery that complicates her treatment for TB.

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.

The doctors deal with trying family matters.

Rhodes tries to save a mother who's determined to help her daughter beat cancer.

Dr. Rhodes clashes with Dr. Charles and other medical staff over how to treat Dr. Charles's daughter Robin.

Robin returns to the hospital with more complications; Rhodes faces competition from a new doctor.

Dr. Choi enlists April's help to figure out how a neighbor got stabbed; Noah misdiagnoses a patient.

Dr. Bekker takes the lead on a surgery, then takes the heat when something goes wrong.

After a shooting occurs during a block party at a local park, Med is overrun with victims that stretch the hospital and staff to its limits.

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.

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.

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.

A sick boy is brought to the hospital, forcing Ethan to face a tough decision that grows into a complicated and dangerous situation.

The CPD pays Dr. Halstead an unexpected visit; Ethan is skeptical of a woman experiencing chronic pain; Natalie takes care of a cancer patient whose brother refuses to help.

Will must lie to Natalie; Ethan and April uncover compromising information about Emily's boyfriend; Ava isn't sure what to do with a patient who doesn't want treatment.

Manning and Halstead work quickly to save a physically abused wife; Choi and April discover a shocking truth about a 14-year-old cirrhosis patient; Rhodes and Lanik face off in the ER.

The ED goes on lock-down due to a deadly chemical spill that threatens the lives of patients and leaves one of Med's own in the balance; Rhodes and Manning attempt to perform live-saving surgeries.

Will and Natalie prepare for their big day, but an unsuspecting Will soon finds himself sidetracked.

Connor, who is in hot water with the hospital's Oversight Committee, handles a gunshot victim with unexpected ties to Halstead. Maggie feels guilty about the return of a former patient. Charles has an awkward first date.

Halstead treats a woman on the verge of freezing to death. Dr. Charles' ex-wife receives some concerning news. Choi handles a lymphoma patient with viral meningitis and a complicated family. Manning makes a house call.

Dr. Manning's actions with a recent patient lead to serious repercussions. April and Noah disagree over a patient who is injured after a beating. Dr. Charles is visited by a childhood friend with a surprising revelation.

Maggie gets unsettling news about a new friend and breaks protocol to support him; one of the doctors from the Med family is rushed into emergency surgery after a violent assault; a social media influencer lets his users vote on medical advice.

A convicted murderer's escape hits close to home when several members of the team find themselves in danger. Dr. Charles and Dr. Halstead continue to clash over patient treatment plans. Dr. Choi and April discover the truth about a patient's scam. Maggie finally receives some good news.