Carter returns from his harrowing mission to Congo, only to be confronted by a hostile Abby. And there is a new arrival, Neela Rasgotra, studying and working at County General.
Carter returns to Congo to search for the body of a fellow doctor and is reunited with several colleagues from his previous trip, but is placed in immediate danger
A frustrating day for Abby gets even worse when she receives an upsetting letter from Carter, who is still in Congo. An apprehensive Pratt meets Chen's parents.
Pratt wants to prove his abilities when he works the graveyard shift (11pm to 7am), but his heroics backfire. Meanwhile, Abby is desperate for money and credit, and Weaver makes a serious error.
Lewis fears for a distraught architect, whose deteriorating eyesight makes him despondent, while Corday learns something shocking about the charismatic Dr Dorset
Pratt and Kovac clash over a miscarriage-prone young woman, who arrives to deliver a premature baby. Meanwhile, Lewis enjoys the company of a sarcastic patient.
To everyone's amazement, Lewis makes a date to share a home-cooked dinner with Ben Hollander, her depressed patient who is going blind, and she also makes plans to meet with the Internal Revenue
On Thanksgiving, the harried staff struggle with a shortage of doctors. Abby treats an HIV-positive woman, Loren, who is haemorrhaging and may be pregnant. A terrible accident threatens the hospital.
Two distinctive cultures come face to face when Neela treats two Amish teenagers who were in a car accident, while Pratt is swept off his feet by the beautiful Valerie
On Christmas Eve, the chilly ER staff do their best to observe the holiday while a crusading Carter does the same, half a world away in a rundown Congolese medical clinic
Carter returns to County General to a hearty welcome, but Abby is shocked to learn that Carter's girlfriend, Kem (Thandie Newton), is pregnant. Pratt's day starts badly and goes downhill.
In a special episode focusing on the neonatal intensive care unit (NICU), medical students Abby and Neela serve a three-week rotation in the unit
Carter makes the mistake of bringing his girlfriend, Kem (Thandie Newton), to observe the emergency room. Meanwhile, Pratt has a difficult night.
A risk-assessment expert is hired to observe the emergency room and is shocked at the mayhem, while Sam treats an abused and newly pregnant teenager
Carter misses his pregnant girlfriend, who has returned to Africa, while a family of four is rushed to the emergency room with carbon monoxide poisoning
A psychotic patient vows to punish the medical staff and steals an army tank, grinding his way across Chicago towards the hospital. One of the emergency room staffers has a heart attack.
Carter urges his student, Neela, to be more proactive in the emergency room, but she goes too far in treating a patient with a brain injury and Gallant helps out, making the situation worse
Weaver rushes to the aid of her partner, Sandy Lopez, when the firefighter is severely injured while working and has to battle for her life. A pregnant Lewis suffers labour pains.
An attractive woman informally accuses flirtatious Pratt of sexual harassment. Meanwhile, Sam tries to resist the appeal of her son's 'reformed' father.
A panic-stricken Dr Weaver faces a life-defining moment when she is ordered to give up her son to the Lopez family, while Dr Carter greets a returning Kem. Abby tries to help a mother with seizures.
When Carter suspects a problem, he rushes his pregnant girlfriend to the emergency room. Corday gets a jolt from the past when the late Greene's teenage daughter shows up.
Neela and Pratt search for an overweight teenager whose blood pressure could indicate deadly heart disease, while Kovac helps a female motorist and her son who are gravely injured