Will and Natalie battle for their lives after a car accident; an investigation is launched following the suspicious death of Cornelius Rhodes; Maggie receives life-changing news; Dr. Charles cuts his honeymoon short to tend to a patient.
A power outage at Med puts multiple patients at risk and tests the skills of the staff and their enthusiastic med students; Natalie returns following her traumatic brain injury; Ethan and April wonder if a family is in their future.
Dr. Choi and Dr. Charles have difficult decisions to make as a dying man tries to preserve his life with a controversial scientific method; Dr. Marcel and April clash over how to handle a mysterious patient; Will questions Natalie's capabilities.
An entire apartment complex is forced into quarantine when cases of a deadly virus turn into an epidemic; P.D. chases a lead that could point to a case of bioterrorism, and Will gets dangerously close to the suspect.
Dr. Choi and Dr. Marcel don't see eye to eye over the treatment of a patient's chronic pain; rumors circulate about Maggie; Dr. Manning works to help a young boy, but she is challenged by his parents, who believe in only using holistic remedies.
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.
Dr. Charles and Dr. Halstead sink their teeth into a bloodthirsty case; Dr. Marcel and Maggie throw a traditional crawfish boil for the staff; a new relationship blossoms while another is left on rocky ground.
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.
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.
Dr. Halstead's world is thrown into turmoil when a former patient resurfaces; April has a secret she considers confessing to Ethan; Dr. Charles tries to maintain his focus during a difficult time.
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 team deals with the aftermath of a school bus crash; Dr. Charles worries Dr. Halstead is putting his medical license in jeopardy; Maggie helps a friend in need.
Two brothers in critical condition are rushed into the hospital by their parents, leaving Dr. Choi, April and Dr. Charles to piece together what actually transpired; Dr. Manning becomes suspicious of a new mother entering the E.D.
Dr. Manning and Dr. Marcel disagree over an abusive husband; Dr. Halstead struggles with ethics and his decision to work at the safe injection site; Dr. Charles and Elsa reveal a misdiagnosis that may change a family's life.
Dr. Charles and Dr. Manning treat a patient who is fully invested in pretending to be someone other than himself; Noah doubts his abilities as a doctor; Dr. Marcel and Dr. Choi face a tough ethical decision; Dr. Halstead puts his faith in an addict.
A convicted murderer's escape hits close to home when several team members end up in danger; Dr. Charles and Dr. Halstead clash over patient treatment plans; Dr. Choi and April discover the truth about a patient's scam; Maggie receives good news.
Dr. Manning and Dr. Charles assist in a complicated case helping a child who is no stranger to the ED; Dr. Marcel and Dr. Choi tend to a police officer with a mysterious gunshot wound; relationships are put to the test as secrets are revealed.
Dr. Charles and Goodwin fear Dr. Halstead is repeating his past mistakes when a patient with early onset Alzheimer's is brought into the E.D.; Maggie and Ben are concerned when one of Ben's students is admitted; Dr. Manning and Dr. Marcel disagree.
Dr. Charles evaluates a 15-year-old who is brought into the E.D. after an apparent fall off an overpass; Will sides with Dr. Asher on a risky treatment plan; tensions run high between Dr. Choi and Dr. Marcel.