The emergency department's grand opening is interrupted by an onslaught of crash victims, pushing hospital administrator Sharon Goodwin and her staff to their limits as they frantically work to triage and treat patients. It's all hands on deck as newly hired trauma surgeon Dr. Connor Rhodes, pregnant paediatrics specialist Dr. Natalie Manning, third-year resident Dr. Will Halstead, military-trained Dr. Ethan Choi, nurse April Sexton and head of psychiatry Dr. Daniel Charles must pull together to save lives. Rounding out the team is medical student Sarah Reese, who quickly learns some of the hard lessons that come with life in the Emergency Department.

As Dr. Ethan Choi treats a bleeding teenage girl, he discovers she's just given birth, sparking a frantic search for her abandoned baby. When the details of the teen's troubled past emerge, Ethan finds himself at odds with pediatrician Dr. Natalie Manning and hospital administrator Sharon Goodwin as they're forced to make some difficult decisions about the teen's future. Dr. Will Halstead treats a hypochondriac with chest pains while struggling to navigate his overbearing wife. Meanwhile, med student Sarah Reese and psychiatrist Dr. Daniel Charles treat a patient suffering from dementia, only to discover she may not have dementia at all.

When Dr. Connor Rhodes takes the case of a close family friend who's been impaled by glass shards, he's reunited with his sister, Claire Rhodes, and forced to confront his past. Meanwhile, Dr. Natalie Manning convinces a young musician to undergo a surgery that will save her life but could destroy her hearing.

After shots ring out at a movie theater, the Chicago Med doctors work to treat the victims while hospital administrator Sharon Goodwin attempts to keep the press at bay. To treat a teenager with an eating disorder, Dr. Natalie Manning enlists the help of Dr. Daniel Charles, but his unorthodox methods rub Natalie and the teenage girl's mother the wrong way. Meanwhile, Nurse April Sexton, Dr. Will Halstead and Dr. Ethan Choi treat a racist patient whose strange form of bigotry surprises them all.

Following a knife attack, a member of the team lies in peril and their condition takes a sudden turn for the worse, leaving Dr. Connor Rhodes and Dr. Toni Zanetti scrambling to race against the clock. Word quickly spreads that some of Connor's fellow doctors feel he should have operated sooner, causing tension at the hospital. Dr. Natalie Manning makes preparations for her pregnancy and Nurse April Sexton's brother struggles through his first day at the hospital. Meanwhile, members of the Chicago P.D. Intelligence Unit help investigate whether the case of a women clinging to life after Firehouse 51 pulled her out of a burning building is attempted sleeping or cuddle. As the investigation deepens, a surprising parallel to other patients surfaces.

(The Beating Heart (1) aired on Chicago Fire, season 4, episode 10. Now I'm God (3) aired on Chicago P.D., season 3, episode 10.).

Two airplane stowaways are brought into the hospital after suffering major injuries from the travel, prompting Sharon Goodwin to receive a visit from the Department of Homeland Security regarding the undocumented immigrants. Cornelius Rhodes, the wealthy father of Dr. Connor Rhodes, is honored after making a big donation to the hospital for a new psych ward, forcing dark family secrets to the surface. Dr. Natalie Manning's big day arrives and Dr. Will Halstead's good intentions to help are misconstrued by her mother-in-law, Helen. Meanwhile, Dr. Sarah Reese asks Dr. Charles for advice on how to deliver heartbreaking news to a young boy while also warning his family about the possibility that their other son may also have the same life-threatening disease.

When legal issues complicate matters that stall a life-saving bone marrow transplant, Sharon Goodwin must decide whether to disobey direct orders, or stand by and put a patient's life in jeopardy. April tends to a caring, homeless man who Dr. Charles evaluates, only to come to an unusual diagnosis that explains his recent behavior. Dr. Natalie Manning's parents come to town to see their new grandchild, much to the dismay of her mother-in-law, Helen. Dr. Connor Rhodes treats a couple who are injured on their first date by a hit-and-run driver, who Dr. Halstead discovers has his own reasons for causing the accident.

Dr. Manning returns from maternity leave and helps treat a teen with a long history of medical issues. Dr. Choi attends to a former Navy shipmate with a potentially life-threatening ailment and goes above and beyond the scope of his duties to ensure he gets the proper treatment. Saudi Prince Faisal arrives at the hospital for a planned surgical procedure, but only from Dr. David Downey, the hot-shot surgeon who takes a shine to the work of Dr. Rhodes. Meanwhile, a budding romance between Sarah and hospital lab tech Joey looks hopeful, but April might think otherwise.

Dr. Halstead revives a "do-not-resuscitate" terminally ill cancer patient, and the repercussions prompt his quick removal from the case and a pending lawsuit against Chicago Med. A homeless man's arrival is passed down to April and an uneager Dr. Reese, but the circumstances surrounding his short stay catch both off-guard. Following the assessment and treatment of a bi-polar patient with an unhealthy dependence for lithium, Dr. Choi's own personal issues come to the surface, prompting him to seek the advice of Dr. Charles. The medical staff is shocked to learn one of their own has a life-threatening disease.

Dr. Rhodes and Dr. Downey make plans to operate on Ray, a 9/11 hero who is suffering from pulmonary fibrosis. A new set of lungs could save his life through an innovative surgical procedure but an unforeseen medical problem arises with Ray that might derail the doctor's grand plans. Sarah contemplates which hospital to select for her residency match while Maggie and April make their push for her to remain at Chicago Med. Meanwhile, Dr. Choi works to determine the cause of an injured teenage star hockey player with an overbearing father while Dr. Halstead and Dr. Manning continue to clash.

Dr. Rhodes and Dr. Choi disagree over the final decision made by a patient suffering from a life-threatening heart condition. The pending lawsuit against Dr. Halstead continues to move forward, and Sarah Reese and Dr. Zanetti scramble to save a patient with a misdiagnosed flesh-eating bacterial disease. Elsewhere, Dr. Manning treats a young girl diagnosed with a contagious bacteria, prompting her and Dr. Halstead to take action to avoid a major outbreak.

Nurse Lockwood gets arrested for refusing to violate hospital policy and draw blood from a suspected DUI patient without his consent. Dr. Halstead discusses with his lawyer the severity of the pending lawsuit against him. Elsewhere, Dr. Manning and Sharon Goodwin deal with a single mother and her 6-month old, but when the baby's injuries come into question, concerns are raised. Meanwhile, Dr. Charles, who is dealing with some personal issues, and Sarah Reese, attend to a patient that was hit by a car, but suspicions abound when they dig deeper.

Dr. Halstead and Sharon Goodwin deal with a husband intent on harvesting his recently deceased wife's eggs, but soon discover some vital information that surprises everyone. Dr. Charles is brought in by Dr. Choi 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 befriends the father of a child who is rushed into the hospital after swallowing magnets - a situation that Dr. Rhodes and Dr. Manning are concerned could present dangerous complications. Meanwhile, Sarah Reese finally learns about where she will do her residency, but has last-minute second thoughts.

An erratic patient comes to the emergency department claiming that his heart is pounding inside his head and takes drastic measures to stop it, leaving Dr. Choi and Dr. Charles to figure out the best course of action. Dr. Manning works on a young boy with a broken wrist, but her suspicions abound when the facts don't add up, prompting her to report the situation to Goodwin and Dr. Charles, who must make a serious decision. Dr. Rhodes impresses Dr. Downey with his skills inside the operating room, but the pressure takes a toll. Elsewhere, Will receives news about the pending lawsuit, April feels a spark in her social life, and Sarah tries to determine the cause of her recent anxiety.

Dr. Manning and Dr. Charles deal with a 16-year-old patient suffering from abdominal pain who adamantly refuses any drugs for fear of winding up like her drug-addicted father. Dr. Halstead relives a bit of his past when a patient, along with his brother, turn out to be former high school classmates whose past history with him is anything but stellar. Meanwhile, Dr. Choi works on a woman 32 weeks pregnant who has a big reason to do everything in her power not to deliver the child, much to the dismay of Goodwin, Charles and the hospital staff. Elsewhere, April is less than thrilled to discover her brother Noah has an enterprising side-business that involves her new boyfriend Tate. Dr. Rhodes avoids meeting up with his sister Claire (Christina Brucato) so he doesn't have to deal with family issues.

When Dr. Rhodes and Dr. Downey treat a patient with a multitude of health and heart issues, they uncover he might be misdiagnosed and disagree over the best course of action. Dr. Choi, riding along with paramedic Sylvie Brett, responds to a call for a man with a leg injury, but complications arise in getting to him since the home is wrought with excessive hoarding. Meanwhile, treating a patient who was bitten by her own dog, Dr. Manning and Sarah have suspicions about the reason for the injury and what it might mean. Meanwhile, Goodwin ensures that everyone is on their best behavior when the Joint Commission makes a surprise visit to Chicago Med to evaluate and rate the hospital's standards.

April and Dr. Halstead handle an alcoholic homeless man with a broken leg, but they don't see eye to eye on how to best treat his illness. Still grieving the passing of her late husband, Dr. Manning experiences a medical event after realizing her wedding ring has gone missing. Dr. Charles and Sarah treat two elderly women with the exact same symptoms, but uncover a surprise that links the two cases together. Dr. Downey and Dr. Rhodes operate on a patient refusing their recommended treatment due to religious reasons. Meanwhile, a frustrated Dr. Halstead considers a job offer in California.

Dr. Rhodes tends to the care of Dr. Downey while Goodwin is forced to deal with personal issues. April bears the brunt of a punch while attending to a disorderly patient, but the incident could actually prove to be a blessing in disguise. Dr. Halstead discovers Goodwin has a trick up her sleeve, and Dr. Manning finds her past catching up with her. Sarah's graduation day finally arrives, but she remains conflicted about mapping out her career plans for the future. Meanwhile, at the urging of Dr. Charles, Dr. Choi turns to an unlikely source for help.