Following the subway tunnel collapse, Ruzek and Kidd treat injured passengers and track down the missing offender. Archer and Frost perform a life-saving amputation. The crossover starts on Chicago Fire S13E11 In the Trenches (I). It continues on Chicago P.D. S12E11 In the Trenches (III).

The team fights to save the life of one of their own. Frost and Abrams butt heads with their patient. Asher helps a religious young woman with an ectopic pregnancy.

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.

Goodwin's troubles persist. Charles clashes with his former resident over a depressed patient. Lenox and Ripley treat a car accident victim who recently reunited with his college sweetheart.

Ripley struggles to rescue a woman and her daughter trapped in an abandoned well. An old friend from Frost's TV days shadows Maggie. Asher discovers an extremely rare condition in her patient's ultrasound.

Asher makes a tough call to save a life. Frost and Ripley treat a young boy with a snake bite. Archer gives Naomi a patient to handle on her own on her last day in the E.D.

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. The crossover starts on Chicago Fire S08E04 Infection (I). It continues on Chicago PD S07E04 Infection, Part III (III).

Charles and Archer treat a heart transplant patient who believes his new heart doesn't want to be in his body. Lenox takes a personal day. Asher discovers a mass on a pregnant woman's ovary.

Asher treats a woman whose undiagnosed condition threatens the lives of both her and her unborn child. Goodwin receives a chilling message while battling the hospital higher-ups.

The hospital faces a staffing crisis as the nurses stage a sick-out. Archer and Frost bet on who can discharge their patients first. Charles' distrust of a patient complicates his treatment.

An army of surgeons prepares to separate conjoined twins. Asher reconnects with someone from her past. Archer treats a tyrannical boss with a heart problem.

Chicago Med braces for an influx of trauma patients when a pre-dawn pileup finds the hospital in full scramble mode. As a result of the storm and emergencies, supplies become limited and Goodwin, Dr. Manning and Dr. Halstead must deal with making an impossible decision. Meanwhile, Dr. Choi handles a severely burned patient who has one final request and Dr. Charles deals with an agitated patient.

A suicide shakes the staff. Dr. Choi and Dr. Halstead face off over how to treat a patient with stroke symptoms. Family turmoil unfolds when a boy is treated after falling in a river. The importance of learning from mistakes is emphasized to Dr. Reese.

A new hotshot doctor arrives at Chicago Med causing competition for Dr. Rhodes, Dr. Halstead and Dr. Manning work together to diagnose a Syrian refugee without a medical record. When Robin is admitted back into the hospital for more complications, Dr. Reese takes a different approach to her treatment. Distracted from work because of Robin's worsening case, Dr. Charles is challenged by Goodwin and Noah hosts a graduation party that brings everyone together.

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).

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.

An infection threatens Marcel's risky liver transplant. Maggie and Charles help a struggling burn unit nurse. Goodwin is forced to make a tough decision about Bert's future.

Ripley and Charles treat a high-risk prisoner who may have dementia. Archer and Sean clash when a resident from Margo's facility lands in the E.D. Marcel receives shocking news.

Gaffney gets a surprise visit from a National Accreditation Board of Hospitals representative. Asher and Naomi search for the cause of a young girl's infection. Lenox and Frost work together to save the victim of an accidental shooting.

Dr. Rhodes treats his mentor and Goodman faces personal issues in the Season 1 finale. Also: April deals with a disorderly patient; Dr. Manning's past catches up with her; and Sarah's graduation day arrives, but she remains conflicted about her future.

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.

The hospital is forced to evacuate when a toxic chemical is brought into the E.D., leaving patients and the staff in grave danger. Stuck in an elevator, Dr. Charles and Dr. Manning are forced to take drastic measures with a pregnant woman. Goodwin is tasked with making difficult choices and Dr. Rhodes discovers a secret that Dr. Bekker has been holding from him.

Caroline has news to share, forcing Dr. Charles to make a serious decision about their relationship. Maggie meets her sister's new boyfriend, but discovers danger may lie ahead. Dr. Rhodes experiences a devastating loss while Dr. Choi and April are faced with an unexpected challenge that strengthens their relationship.

April receives unfortunate news that makes her question her future with Ethan. Dr. Charles and Maggie see tough times on the horizon. Natalie’s memory from the accident starts to return.