Abby, Pratt and Morris clash with Moretti's strict new ER procedures as victims of an anti-war rally roll in, including Neela. Gates manhandles a patient he suspects set off the explosion that disrupted the protest. A worried Dubenko lets his emotions for Neela take over during Neela's surgery. Meanwhile, the rest of the staff worry over Neela's condition.

Patients include a pregnant teacher whose student/lover was critically injured while driving; a man who is hiding a gunshot wound and a brilliant young boy who knows he is dying, but hides it from his mother. Dr. Moretti continues to remake the ER to his liking, Neela is recovering, Luka's absence is reinforced (back in Croatia and not coming back) and Sam may be starting a new relationship with a police officer.

Abby and a distracted Morris work to save two auxiliary cops brought in with gunshot wounds. Pratt treats a teen wrestler with severe vomiting, but the problem is much more serious. Sam worries over her new beau Litchman. Gates tries to help a young boy in the ICU with a deadly disease. Also, Dubenko visits Neela while she babysits baby Joe.

When Baby Joe is injured by a fall at the playground and rushed to the hospital, Abby is unable to reach Luka to tell him.

Moretti brings in new attending Skye Wexler to help with the patient load. Morris and Pratt cram for the medical board exam. Gates treats a returning patient from the ICU whose condition has worsen. Sam tends to a teenage girl who is feeling neglected by the staff. Neela's intern, Harold, seeks her advice on a personal matter. Abby struggles with her relapse.

The city suffers power outages during an unseasonably hot spell. Nursing-home patients are brought into the ER suffering from hyperthermia. Abby and Pratt disagree on the diagnosis of a fussy baby. Abby falls back to old habits and quickly spirals down to rock bottom on a night she'll forever regret.

Dr Wexlar is made interim ER chief while staff deals with an industrial accident that leads to a hate crime.

Morning shift begins. The night shift treated 142 patients - a new record. Dr. Morris is confident that by the end of the day the ER can set a new record of 300 patients. Frank reminds him that there has never been more than 250 patients in a day. Dr. Morris bets $300 that they can reach 300 by the end of the shift. Frank, Dr. Gates and Dr. Pratt each bet $100 against him. But will the game be fair? Also, when chaplain Dupree arrives announcing that she's doing a round of the hospital, holding blessing ceremonies and memorials, the guys are against it, except for Dr. Gates, which makes the others suspicious. Frank goes straight to the point. Then there is the accident involving a camel.

Dr. Pratt applies for the job of ER Chief and gets turned down. This causes him to give 2 weeks notice. A female soldier, home 2 weeks from Iraq, is 2 months pregnant and her husband demands an explanation. Neela's cousin has arrived from London for an extended visit and gets pursued by both Dr. Morris and Harold Zelinsky. After 9 years absence, a fall in gym by her son brings Jeanie Boulet back to the ER. Not only is she troubled because of her son, but the disorientation of knowing virtually no one on the current staff does not help.

A firefighter is brought in after being injured at a fire that is blamed on a young girl with genetic problems. Abby decides to prove the girl did not cause the fire. A disfigured man saves his anti-social neighbor. An old woman dies unattended at the ER while the staff are waiting for a psychiatrist. Pratt backs up Abby in an administration meeting. Neela's cousin apparently chooses Harold.

Pratt gets cold feet when Bettina tries to take their relationship to the next level. Neela joins the Ortho's hockey team and is shocked to see who their opponents are in the first game.

The ER is on guard as Gates gathers the new interns to treat a terrorist, but it's the new doctor and her tough disposition that has everyone on the defensive.

When a gunshot wound victim arrives, the new chief and Abby butt heads on how to treat the patient. Abby comes to Sam's defense when she goes before a nurses disciplinary board.

A woman who broke her leg while trying to escape a house fire is brought in with her husband. The husband, Mr. Lotery did not let the paramedics to check him over. Then his brother-in-law arrives, saying that he predicted that something like the house fire would happen - it was actually an arson. Mr. Lotery's brother-in-law becomes aggressive and accuses him of being a pervert, specifically a pedophile. Mr. Lotery denies the accusations. He was sued but found not guilty. When Mr. Lotery is waiting for his wife who's in line for X-ray, he has the chance to calm down a young girl who is afraid of needles. When his brother-in-law sees this, he brutally assaults him, while Dr. Brenner calmly watches nearby... Meanwhile, Neela gets sued for malpractice.

As a snowstorm hits Chicago, Sam's son Alex crashes a car and ends up in critical condition in the ER. Neela gives a deposition in the malpractice suit against her. Dr. Morris and Dr. Banfield are both at a medical conference in Omaha, and when the snow cancels all flights out they share a memorable and surprising evening.

The police wheel in a casualty of a drug deal-turned-shoot-out. They also bring in an injured woman who was the shooter, plus a pair of wounded brothers who were shot by the man who was shot dead. A 13-year old girl with sickle cell disease is brought in because of abdominal pains; Neela takes her case while Tracy learns from her. Banfield's pregnancy test is negative, which leads to a discussion with her husband and a visit to a specialist.

A girl who was hit by a car while riding a bicycle is treated in the ER. When her boyfriend turns up, it seems it may not have been an accident. While a lottery has made millionaires of several nearby convenience store workers, Dr. Banfield and her husband are at the fertilization clinic hoping for their one in a million chance. And as an older woman is brought in assisted by her on-again, off-again husband, three love stories continue in the ER: Dr. Morris meets policewoman Diaz again, Sam discovers that Tony has been seeing Daria, and Neela plays it cool with the returning Dr. Brenner.

An elderly man is brought into the ER after being mugged, and sees things as if it were the 1960s.

A single mother is hurt in a car accident, and must find someone to take care of her daughter. Gates treats a 78-year-old man who refuses surgery that would save his life. Meanwhile Morris's afternoon date with Claudia is not what he expected.

Dr. Carter returns to Chicago and talks Dr. Banfield into allowing him to pick up a number of shifts (without pay). Other happenings include Banfield's dogged pursuit of motherhood, Neela's intensifying personal relationship, and Archie's involvement with a patient who was probably beaten while in police custody - with his new girlfriend the detective standing by.

Banfield and her husband look into adoption, while Carter adjusts to a changed ER. Sam's mother comes into the ER in an altered state of mind.

Carter's illness overtakes him during a critical procedure in a trauma room as a documentary film crew spends the day interviewing the health care givers.

On Neela's last day at County, she has doubts as to whether she is making the right decision.

A girl who was hit by a car while riding a bicycle is treated in the ER. When her boyfriend turns up, it seems it may not have been an accident. While a lottery has made millionaires of several nearby convenience store workers, Dr. Banfield and her husband are at the fertilization clinic hoping for their one in a million chance. And as an older woman is brought in assisted by her on-again, off-again husband, three love stories continue in the ER: Dr. Morris meets policewoman Diaz again, Sam discovers that Tony has been seeing Daria, and Neela plays it cool with the returning Dr. Brenner.

Abby, Pratt and Morris clash with Moretti's strict new ER procedures as victims of an anti-war rally roll in, including Neela. Gates manhandles a patient he suspects set off the explosion that disrupted the protest. A worried Dubenko lets his emotions for Neela take over during Neela's surgery. Meanwhile, the rest of the staff worry over Neela's condition.