Morgan and Park diagnose elderly patient Harvey with kidney cancer and compete over who will lead the surgery, as new Chief of Surgery Lim will allow third-year residents to do so. Due to Harvey's dementia, the two come together to convince his wife to leave the cancer untreated so that he can enjoy his remaining time. Melendez, Shaun, and Claire treat a newlywed bride with extensive cancer. Shaun proposes a radical, high-risk surgery. With the support of her new husband, she successfully underg
Morgan and Park continue to compete for who will perform the first surgery, but Lim chooses Claire. Lim and Melendez find themselves at odds over the treatment of a baby whose parents and evidence suggest that Melendez erred in a previous surgery; Melendez is ultimately exonerated and he and Lim save the baby together. Andrews, Shaun, and Claire treat a Good Samaritan who had the side of his face destroyed while saving a total stranger. Andrews refuses to give up on the patient and saves his fac
Morgan and Park treat Shamus O'Malley, a man with a giant marlin impaled in his leg and who is more worried about the fish's safety than his own; the injury causes the doctors to discover that Shamus has cancer, requiring an amputation. Shaun develops doubts about his relationship with Carly after Claire points out that he asked many invasive questions for a new relationship; it turns out that Carly didn't mind Shaun's questions and orders Claire to butt out of their relationship. Claire treats
Andrews, Park, and Shaun treat Mitchell, a conspiracy theorist with a genetic liver disease and a belief that someone poisoned him; Shaun eventually realizes that Mitchell was inadvertently poisoning himself daily with herbs he'd been taking for virility. Melendez, Claire, and Morgan treat Lily, a woman who's unable to feel physical or emotional pain, resulting in a ruptured appendix and amputated hand. With her husband contemplating leaving her because he believes she cannot feel love without p
Morgan and Claire treat Curtis, a man who comes in intoxicated despite supposedly being sober for over six years. Claire, who is still struggling with her mother's death, refuses to believe Curtis is telling the truth about his sobriety while Morgan searches for an alternative explanation; Curtis turns out to have a benign tumor that was causing his intoxication. At the same time, Glassman becomes uncomfortable after learning that Debbie owns a gun and attempts to dissuade her without success. S
Shaun's first lead surgery is an appendectomy; though it is successful, Shaun kicks Nurse Hawks out of the OR for handing him a tool in a way other than his preference. Shaun's inability to apologize escalates the situation; Hawks files a formal complaint and Lim threatens to fire Shaun if another such incident occurs. Melendez, Park, and Morgan treat Patty, a twenty-three-week pregnant woman with an ovarian tumor. The team and the parents clash over Patty's treatment as both Melendez and Patty
Melendez continues to struggle with the death of Patty, resulting in him taking more caution with patients. After an intervention by Glassman, he tells Lim that he thinks they are both at fault due to their relationship removing objectivity from the decision to approve the surgery. Debbie's efforts to help in the clinic lead to an argument with Glassman. Andrews, Claire, and Morgan treat Charlie, a boy who is about to lose his sight due to cancer. Morgan and a reluctant Claire take Charlie on a
Melendez's continuing hesitation to take risks puts him at odds with Lim over the treatment of Wren, a young woman who plans to travel to the moon and thus needs both of her lungs intact; working together, Lim and Melendez successfully perform her surgery. Lim ends their relationship since she can't pursue her dreams and be everything Melendez needs at the same time. Morgan is assigned her first lead surgery; Andrews reveals that he believes Morgan has it in her to be a leader. Privately, she re
Claire's self-destructive behavior leads her into a moral dilemma when her latest one-night stand arrives in the hospital following a car accident and turns out to have a family; at Claire's urging, his wife forces him to tell her the truth, leading to Claire getting publicly slapped. Morgan, Shaun, and Andrews treat Jeanie, a young woman who refuses to have life-threatening tumors removed because it would also remove her ability to have sex; Morgan convinces Jeanie's fiancé to get her to have t
Claire, Melendez, Park, and Morgan treat Art Kalman, a professional football player who broke his back at the gym. Morgan's suggested course of treatment proves effective and he is expected to be able to return to football, but Art reveals that he hates the sport and felt pushed into it, purposefully injuring himself as a way of getting out. After Art explains he feels obligated to his family, particularly his mother, Claire uses her own experiences to convince him to be honest with his family a
Park and Claire treat Luca Jones, a man who became a drug mule after falling on hard times; Claire clashes with Park over whether or not to turn Luca into the police, sympathetic with his circumstances. Luca later flees the hospital with drugs that were surgically removed from him, suggesting that Park was right about him. Claire continues seeing a therapist who suggests that she has PTSD. Shaun and Morgan treat Kerry, a patient with a badly broken leg who refuses painkillers or anesthesia due t
Shaun, Morgan, Andrews, and Lim treat James, a man who is suffering swelling due to a genetic mutation which makes his treatment extremely difficult; if not properly treated, he will drown in his own fluids. As a result, Carly is called in to help the team, but she struggles with dealing with a live patient rather than samples; Carly and Shaun's research using zebra fish ultimately finds a treatment that saves James' life. At the same time, Claire, Park, and Melendez treat Angie, a cancer patien
The team treats Caroline Reznik, an artist who needs a lobectomy to treat her cerebral cavernous malformations; Caroline turns out to be Morgan's long-estranged mother and it is revealed that she is from a family of famous artists. Morgan eventually finds another solution that she and her brother Ariel get Caroline to accept; after some convincing, Glassman successfully performs the surgery. At the same time, Shaun and Melendez treat Oliver, a man dying of cancer who is determined to live life t
Claire, Park, and Melendez treat Ann, a mother who fell ill after trying a home remedy she found on the Internet for her urinary tract infections. Ann's diagnosis helps discover serious heart ailments in her three-year old daughter Marla. Marla soon has a heart attack, but the doctors successfully treat her and promise Ann that, with lifelong medication, Marla should enjoy a long and healthy life. Meanwhile, Shaun, Morgan, and Andrews treat Kayley, a social media influencer. During Kayley's surg
Lim, Morgan, and Shaun treat Cory, a young boy born without a fully-developed trachea or larynx; after an experimental surgery to give him a trachea, Shaun comes up with a way to give Cory a larynx. Morgan is revealed to have been the one to file a complaint against Melendez and she shows increasing signs of deterioration from her rheumatoid arthritis. At the same time, Melendez, Park, and Claire treat Fran, a firefighter who suffered a serious arm injury in a dog attack. Tensions rise between P
An elderly Jane Doe comes into the ER with an aneurysm and dies on the operating table. Shaun becomes convinced that there is more to Jane's death and works to find Jane's family. He and Park locate her son Jules. Shaun learns that the Jane Doe, Maribel, had a rare deadly condition that Jules inherited. At the same time, Morgan, Andrews, and Claire treat Aiden Porter, a young man who injured himself and subsequently displays blackouts and sleepwalking, during which time Aiden has a completely op
Shaun, Melendez, and Claire treat Alice Gottfried, who has a rare condition that requires her adrenal glands to be removed. With Alice refusing the treatment, Shaun invents a better surgery that is successful and which Melendez allows Shaun to perform himself. At the same time, Andrews, Morgan, and Park treat Wes Keeler, a survival instructor for at-risk youth who has developed a serious infection from a cactus prick, requiring a kidney transplant. One of his mentees, Max, proves to be a match,
Shaun, reeling from Lea's double rejection, returns after three days at home and works with Claire and Melendez to treat Finn, a patient with a breathing disorder and two girlfriends; one learns of the other and vandalizes Finn's car. Shaun gets drunk and plans to vandalize Lea's car, but she catches him in the act and Shaun instead shouts at her about her negative feelings towards his autism. Park, Morgan, Lim, and Andrews treat a farmer who has pain and limited strength after having had both a
Melendez, Glassman, and Lea are attending a charity fundraiser at a brewery for Marta, one of Melendez's former patients. Marta's wife, Noreen, gives them a tour of the brewery when a massive earthquake hits, trapping Lea in the basement and injuring Melendez's head. Lim organizes assistance at the brewery while Andrews oversees the E.R., but Morgan takes charge when Andrews starts operating with Glassman. Shaun looks for Lea while Park and Lim treat Casey, a young man trapped under a beam. Park
Lim and Park's surgery on Casey fails; Park remains with Casey, who reveals that he blames himself for his mother's death and wants to make amends with his father for his perceived mistake. With Casey's father unable to make it in time, Park pretends to be him to give the young man peace before he dies; the experience causes Park to decide to move back to Phoenix to be closer to his family. Lim returns to the ER where Claire calls her in to help treat Melendez, who has internal bleeding; while p