Anspaugh retires as chief of staff and appoints Romano as his replacement. Weaver becomes chief of emergency medicine. New doctor Luka Kovac impresses Hathaway with the way he treats a young patient.
Greene returns from his mother's funeral and argues with Weaver over a dying patient's wishes. Romano appoints Corday as associate chief of surgery. Carla tells Benton that Reese may not be his son.
Jeanie is able to foster baby Carlos. Benton ponders getting a DNA test to prove he is Reese's father. Elaine has a mastectomy. Weaver introduces Greene to distinguished physician Dr Gabriel Lawrence.
Hathaway befriends Meg, an out-of-work waitress who is seven months pregnant but can't afford prenatal care. Lucy notices Dr Lawrence's memory is failing. Cleo misdiagnoses a four-year-old girl.
A prank in a high school science class goes badly wrong, injuring a teacher and several students. Hathaway discovers Meg's drug addiction. Weaver and Greene realise Dr Lawrence gets easily confused.
Jeanie resigns in order to spend more time with her son. Greene and Weaver use deception to convince Dr Lawrence that he needs help. Hathaway has Meg arrested in an effort to get her off of drugs.
Weaver tries to save a rape victim's life. Cleo helps a teenage alcoholic. Dr Lawrence treats his last patient, and Weaver offers Kovac a permanent position as his replacement. Hathaway visits Meg.
Corday spends a stressful Thanksgiving with Greene's family after he rushes away to help Hathaway deliver her twins, assisted by nurse Abby Lockhart. Malucci impresses Carter with his knowledge.
One of Corday's patients, a rapist, taunts her while she treats him. Kovac and Haleh care for Hathaway's twins so she can get some rest. Lucy strives to obtain a heart transplant for a young woman.
Kovac tells Weaver his wife and children died in the Bosnian war. Jing-Mei Chen returns to County General as a resident and tries to assist a young runaway. Greene invites his father to live with him.
Lucy's patient finally gets a heart transplant. Greene interferes in a domestic situation. Malucci tries to close an illegal pharmacy. Hathaway returns to work but suffers from post-partum depression.
Third-year medical student Abby Lockhart begins her ER rotation as a flu bug hits the hospital. Corday's mother Isabelle arrives in town. Kovac and Hathaway treat a chronically ill three-year-old boy.
Kovac must tell two injured children that their parents didn't survive a car accident. Malucci and Chen are so competitive that they fail to listen to their patient. Lucy needs Carter's assistance.
Weaver arrives at work to find Valentine's Day celebrations in full swing. In the examination room, she stumbles upon the horrifying sight of Carter and Lucy, who have been stabbed by an assailant.
Greene and Corday are stunned to discover that her mother and his father have begun an affair. Kovac witnesses an accident and saves the young victim's life. Carter has excruciating physical therapy.
Carter prescribes a controversial procedure for a suicidal patient. Corday must keep a brain-dead patient alive long enough to harvest vital organs. Greene's father refuses treatment for lung cancer.
Chen's patient refuses to inform his daughter that she might have inherited a condition from him. Weaver defies Romano's authority and is suspended. A prescription mix-up almost kills a patient.
Corday refuses to perform exploratory surgery on Cleo's patient, a teenage car accident victim, so Cleo enlists Benton's help. Abby treats a pregnant woman with five children who wants a termination.
Carter seeks help because he can't sleep after the traumatic attack. Weaver returns to work after her suspension. Hathaway and Kovac share a kiss. Benton's sister thinks Cleo isn't serious about him.
Weaver reprimands Carter for carrying out a dangerous procedure without consulting Kovac, and tackles Hathaway about her lack of focus. Malucci and Cleo discover a six-year-old girl has been abused.
Hathaway comes to a realisation after resuscitating a terminal cancer patient to allow her to say goodbye to her family. Greene prepares to bury his father. Chen worries about Carter's mood swings.
Benton and Kovac rush to a school where a shooting has occurred. A heavily pregnant 18-year-old arrives bleeding from a knife wound. Abby discovers Carter has been illegally injecting pain medication.