A runaway truck nearly hits Hathaway, but still manages to send many people to the ER. Carter treats his cousin's ex. Greene and Weaver join forces to thwart Romano's ascension to chief of staff. Benton tries to stop Carla from taking Reese out of the country. Two new doctors (Luka Kovac and Cleo Finch) join the ER.
Weaver and Greene fight over how to treat a dying teen. Carter and some paramedics fight over turf when he rushes to a nearby accident site. Elaine stops by the ER to see Carter. Jeanie connects with an abandoned HIV positive child.
Greene is frazzled by a new nonchalant legendary physician. When a shooting victim ID's their attacker, gunshots explode in the ER. Kovac tries to protect a woman from spousal abuse.
Cleo initially misdiagnoses a little girl patient. Greene tries to help his father through the difficulties of a car accident. Carter visits with Elaine. Hathaway gets a pregnant woman into the ER for a look-over. Romano abuses his power as chief of staff.
A high school science lab explosion fills the ER with patients. Hathaway and Lucy try to save a pregnant woman and an artist, respectively, from drugs. Malucci finds himself stepping on toes when he asks around about Weaver's injured leg.
Weaver has doubts about Lawrence's mind. Hathaway tries to pull another pregnant woman away from her addiction. Carter is assailed by staff and a father who wants him to cover up his son's diabetes for health insurance purposes. A new desk clerk starts work in the ER.
Lawrence is diagnosed and treated for his mental condition. Greene wonders where his father has disappeared when he doesn't show up for Thanksgiving as planned. Hathaway visits new mother Meg. Lucy has doubts about two of her patients treatments. Corday, Weaver and Kovac treat both the victim and perp of a crime.
Hathaway goes into labor early and her coach, Greene, is off spending Thanksgiving with Corday, his father and his daughter.
Carter inadvertantly starts a guns for gifts movement. Lucy tries to keep a woman in need of a heart transplant alive. Finch sends a teen into alcohol rehab.
Chen treats a young runaway. Corday tries to get the criminal she's been treating to yield the location of a woman's body. Greene has to leave the ER when he learns that his father has gone missing.
Lucy is hopeful that a heart will come through for her patient Valerie, regardless of the complications that arise. The water is shut off to the ER which brings about some difficulties. Nurse Hathaway battles Post-Partum depression. Corday has words with the criminal whose life she saved.
Abby Lockhart joins the ER as a med student and, as is tradition, has a tough first day. Corday tries to deal with her mother's visit. A flu bug hits Chicago and, more spefically, the ER.
Valentine's Day in the ER means a party and crime. Lucy tries to help a law student who shows signs of schizophrenia. Chen and Malucci's quest to one-up each other ends up hurting a patient. Finch, Kovac and Benton work to save the lives of two children's parents who were injured in a car accident. Lucy and Carter are stabbed.
Valentine's Day continues as the ER doctors work on two of their own, Carter and Lucy, and only one of them ends the day alive. The police search for the missing patient/suspect in their stabbing.
Kovac witnesses a girl struck down by a reckless driver and fights to get her to the ER and save her life. Hathaway consoles a teen with cervical cancer who is afraid to let her parent's know. Greene and Corday are taken back when they find out that their parents are becoming close.
Carter, crutch-bound and recovering from the attack, returns to work in the ER. Greene juggles a tough shift which includes trouble with his father and a Gila monster. Abby's treatment of a dying patient could prove fatal.
Kovac faces a crisis of deciding who will receive a kidney when the organ becomes available. Romano slums it on the ER and ruffles feathers. A former patient of Carter's causes him some discomfort when he has to explain why he didn't report a previously existing condition of diabetes. Finch and Benton face Romano's wrath over hazardous sloppy prescription writing.
Benton is caught in a tug of war between current love interest Finch and past love interest Corday over a young boy's surgery. Abby tells an already overworked mother of five that an abortion might be a good choice. Greene takes over caregiving duties when his father chases his at-home nurse away.
A potential bone marrow donor's mother denies the request because of ill will towards the recipient's father, the mother's ex-husband. Greene, unable to take care of his father's worsening condition, admits him to the ER. Kovac takes Hathaway car shopping. Benton takes Finch to meet his family. Carter has trouble coping with his near-death experience.
Kovac comes under fire from Benton when a patient under his watch is neglected to the point where he might lose his leg. Chen learns that a simple test could've saved a child from a life of mental disability. A young girl tells Malucci she's been abused by her father.
Weaver pulls no punches when she singles out people for improper behavior in the ER. Hathaway defies Weaver and procedure in keeping a DNR alive. Greene mourns his father's passing and decides that he should embrace his family and spend more time with his daughter.
A shooting at a school fills the ER with both victims and perpetrators. Kovac fights to save the life of an unborn child whose mother would let it die. Multiple doctors in the ER call Carter on his behavior since the attack. Greene tries to talk sense into a headstrong rugby player.