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.

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).

Dr. Choi and Dr. Marcel don't see eye-to-eye over the treatment of a patient's chronic pain and rumors start to circulate about Maggie. Dr. Manning works to help a young boy, but her treatment suggestions are challenged by the parents who believe in only using holistic remedies.

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, forcing Dr. Charles to make a decision.

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.

Dr. Manning and Dr. Charles assist in a complicated case helping a 4-year old who they quickly learn is no stranger to the ED. Dr. Marcel and Dr. Choi tend to a police officer with a mysterious gunshot wound to the abdomen. 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 become concerned when one of Ben’s students is admitted. Dr. Manning and Dr. Marcel treat a terminally ill patient and disagree over the best course of action.

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.

Dr. Crockett is visited by two New Orleans detectives who have questions about his past. Dr. Choi puts his life in danger to save a child. Dr. Charles gives fatherly advice to his young daughter.

The staff adjusts to the new normal of the pandemic. Dr. Choi, Dr. Lanik and April fight on the front lines. Dr. Halstead and Hannah face a troubling reality. Dr. Charles tries to clear the air with his daughter following recent developments.

Goodwin announces a new ED Chief and the choice doesn't make everyone happy. Dr. Manning takes a stand for her patient and finds herself dealing with the repercussions. Dr. Charles tends to family affairs.

Vanessa and Archer disagree on how to handle the victim of a motorcycle accident. Dylan and Charles deal with a UNICEF negotiator with repressed trauma. Stevie and Will treat a high schooler with Addison's disease and a clingy mother.

The outcome of Will's investigation weighs heavily on his mind as he works with Dylan to save a 4-month-old patient. Stevie and Vanessa both struggle to keep their secrets. Crockett and Blake work with Abrams to save a patient in need of a liver transplant.

Scott suspects his patient may be a drug dealer. Halstead must decide how to spend his whistleblower settlement. Charles and Taylor help a patient who believes she's infested with parasites. Marcel and Blake are paired with an arrogant surgeon.

Halstead helps a patient with long-haul COVID-19 symptoms. Taylor reflects on her dating life when she learns that a patient's daughter is having an arranged marriage.

Rival gangs bring their war to Med. Halstead and Charles work with a brain cancer patient who's refusing treatment. Tensions run high in the OR when a patient's transplanted uterus fails.

Dylan and Ethan treat a patient shot during a drug raid. Charles and Vanessa work together to properly diagnose a motivational speaker. Will and Hannah must turn to Crockett for help with a patient who's pregnant.

Supply chain disruptions dramatically impact Med, causing Marcel to clash with other doctors. Maggie reveals something to Ben. Choi and Archer help a patient with ALS.

When a subway train goes off the tracks, Marcel volunteers to help the victims. Taylor and Halstead must decide if they’re willing to risk their jobs to save a patient. Asher and Archer clash over a pregnant patient.

The fate of the hospital rests on the vote of an incapacitated board member. Archer helps a mother with a rare stem cell disease while Asher treats the woman's pregnant daughter. Charles encounters a schizophrenic patient with a hearing impairment.

Frustrated with an insurance company, Ahmad takes matters into her own hands, jeopardizing Med's negotiations and Marcel's first day on the board. Charles helps a woman's depressed husband. Asher's first date takes a surprising turn.

Archer, Asher and Charles encounter an expecting father who claims he's telepathic and receiving messages from his yet-to-be born son. Ahmad works to thaw out a frozen criminal.

Maggie's budding romance takes flight. After a woman's shocking suicide attempt, Charles searches for answers. Asher works to diagnose a patient who is new to the city and appears with mysterious symptoms.

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.