Season 9 · Episode 1 — Chaos Theory

After another hospital shuts down, the ER is flooded with patients. Dr. Pratt resuscitates a heart-attack victim who had been pronounced de…

Dr. Carter leads a walk-out of staff protesting lack of security in the ER.

Weaver makes a mistake on live television while demonstrating flu shots, inadvertently sticking two reporters with the same needle. In the…

On a busy Halloween night, Carter and Abby are the only staffers in costume when victims of an apartment building fire pack the ER. Corday…

Corday clashes with new surgical resident Paul Nathan regarding his intervention into the treatment of a sickly young woman, Alison, who ha…

Abby fears the worst when her brother Eric suddenly disappears. Carter and Chen treat a frightened Chinese immigrant nanny, Tong-Yi, whom t…

Abby's family nightmare continues as she and her mother Maggie search for Abby's missing brother Eric, who Abby suspects is suffering from…

Abby is distressed when her mother interferes with Eric's treatment at a psychiatric hospital. Pratt treats a frightened young girl who has…

Dr. Kovac's speeding causes a crash on an icy road. The ER staff treats angry elves and a female hockey player with a head injury.

Dr. Pratt brings a gun into the ER; Dr. Weaver tries to conceal her pregnancy; a woman plots against her dying husband; Dr. Chen treats mat…

Dr. Weaver is in a difficult situation when an alderman tests positive for syphilis. Dr. Carter is impressed when he meets a man who runs a…

Dr. Pratt's disabled roommate leads him to a wounded thief. Dr Carter decides to practice medicine in Africa. A doctor makes a pass at Dr.…

Abby's troubled brother is missing. A car runs into a crowd of teen girls. The alderman with syphilis gives Dr. Weaver a promotion. Dr. Lew…

Abby comes close to breaking down trying to deal with her mother. Dr. Pratt goes for his required paramedic ride-along. Dr. Weaver confront…

The police question Drs. Pratt and Gallant about a rampage at the diner across from the ER. Dr. Lewis befriends her teen admirer, a cancer…

Dr. Weaver bends the rules and treats the Alderman's lover for syphilis. Dr. Kovac's patient claims she was sexually abused at a boot camp…

Dr. Romano seizes control of the ER and manages to offend everyone. Dr. Kovac asks Dr. Corday's help in the quest to bring a sickly Croatia…

A psychotic patient threatens Abby. Dr. Weaver suspects a woman poisoned her own baby. Dr. Romano continues to make rash judgments.

Dr. Carter tries to prevent a grieving gang member from going after vengeance. Dr. Kovac races against time to save a Croatian boy's life.…

Carter's day shift and Pratt's night shift (his final shift at County) are intercut. Both men have extremely busy days. Doc Magoo's burns d…

Carter travels to the Congo after Luka calls and asks for help. During the course of his two weeks there, he learns how much different the…