Susan Lewis has a run-in with Dr. Jack Kayson, the cardiology attending, when he accuses her of not providing him with all necessary information on a patient who subsequently died. He makes it very clear that Susan will bear all responsibility for his death. Her sister Chloe informs her that she and her boyfriend are moving to Texas. John Carter is still frustrated by Peter Benton's apparent lack of interest in teaching him anything but a new go for it attitude leads to an invitation to assist in a surgical procedure. Benton's sister suggests to him that the time has come for them to put their mother in a care home.

Carol Hathaway goes ahead with her plans to adopt Tatiana, but her past history makes her ineligible. Benton continues to trade shifts so he can spend time with his mother but it all catches up with him and he has a run-in with Dr. Hicks. Doug Ross treats an abused child. Green, Benton and Carter take extraordinary measures to save a man they later learned had signed a DNR. A consultant arrives to study procedures in the ER, but all is not quite what it seems. Mark Green's wife Jen has an important announcement. Benton's mother has a serious accident when he falls asleep on the couch.

Encouraged by Carol, Mark finally asks Susan out. Benton tries to save a boy, despite the fact Doug thinks he's brain dead.

Carol worries about her physics exam while Mark is heart-broken about Susan's departure and focuses solely on his job.

Doug treats a dying 17-year old cystic fibrosis patient who doesn't want to be resuscitated. Carter gets to operate on Benton.

Carol will hear whether her suspension is permanent or not. Mark and Doyle do what they can to get a patient with Down syndrome on a heart transplant list.

Jeanie asks Greg to help Al get into a special AIDS-program at the hospital. Olbes brings in her grandfather, who had a stroke.

Anspaugh is furious when Carter tells him he wants to quit surgery. Charlie is brought in with an overdose. Mark keeps struggling with his beating.

Cynthia Hooper starts as the new desk clerk. Benton and Carla disagree over whether or not their son should be circumcised. Al gets in an accident at work.

Al wants to move to Atlanta where he got a job offer. Jeanie however isn't keen on moving. Carol talks to Carter's grandmother about the clinic.

Kerry starts to doubt the methods of Synergix. Carter tries to help his cousin beat his drug addiction. Jeanie becomes Scott Anspaugh's part-time caregiver.

Dr. David Morgenstern returns after a six-month absence recovering from his heart attack. His new outlook on life however has Kerry Weaver questioning his abilities. Elizabeth Corday decides to start a study on the use of artificial blood in the ER, but the only problem is that she fails to discuss it first with Rocket Romano. Doug Ross decides to apply for an ER attending position. Scott Anspaugh suffers a major relapse. Anna Del Amico is confronted by an irate husband who wants his ill wife to terminate her pregnancy. At the free clinic, Carol Hathaway has to deal with the case of an underage high school student who is sleeping with her 40-year-old teacher. Peter Benton hits a pedestrian with a car but Carter helps him out with an important piece of information.

When a compatible bone marrow donor cannot be located, Scott Anspaugh agrees to undergo a new round of chemotherapy, even though there appears to be little point. Doug Ross suggests to Jeanie Boulet that Scott may have agreed to the therapy because of her. Mark Greene has taken on the task of organizing the annual ER banquet only to find that Jerry, on whom he had been relying for much of the preparation, hasn't quite delivered. John Carter confronts his grandmother when he learns that she has cut off funding for Carol Hathaway's free clinic. In the OR, Peter Benton has a major confrontation with Dr. Morgenstern, pushing him aside and taking over an operation. Greene and Weaver criticize Doug Ross over his handling of a sick child and her mother.

Following the incident in the OR, Dr. Morgenstern and Dr. Benton present the case to their colleagues. As a result, Peter Benton finds himself suspended for insubordination pending a full inquiry. Jeanie attends Scott Anspaugh's funeral and has some information to share with the boy's father. Anna Del Amico finds herself ethically unable to perform an abortion and is taken to task by Dr. Weaver. John Carter gets the hospital to take legal guardianship of a patient he feels has been subjected to elder abuse, but subsequently doubts that he made the right decision.

Assisted by Carol Hathaway, Doug Ross decides to detoxify a drug-addicted infant in the ER without telling anyone. Jeanie Boulet is feeling rundown and fears that her health may be deteriorating. John Carter is less than pleased when Anna Del Amico's former boyfriend shows up in the ER conducting a study on the need for a pediatric attending physician. Del Amico also has to treat a televangelist who is using her health issues to raise money. Elizabeth Corday is worried that Rocket Romano may be aware of her affair with Peter Benton and that it will affect her fellowship.

At the hospital daycare, one of the child-care workers suggests to Peter Benton that he may want to have baby Reece's hearing checked. Doug Ross dodges a bullet by admitting upfront his error in detoxifying a baby without permission. Having been acting Chief for over 6 months, Kerry Weaver puts her name forward to replace David Morgenstern as Chief of Emergency Medicine only to be told she will have to compete for the job. The doctors treat a couple of Elvis impersonators who sky dive into Lake Michigan. When drugs go missing from the ER, John Carter suspects Anna Del Amico's ex-boyfriend.

Lucy finally admits to Carter that she doesn't know how to start an IV. Weaver interviews for the job as the ER Chief. Benton keeps his son's disease a secret. Jeanie intervenes when she finds out a liver transplant candidate is drinking again, and later asks Doug if she can be assigned to work for his pedes project in the ER. Corday gets stuck as the intern of dismissive and insulting Dr. Dale Edson.

A man arrives at the ER with his gravely-injured daughter then runs out, presenting a critical situation because he's the only match for her blood type. While Carter and Lucy alternately bicker and work well together as they try to track down the father, blood-supply snafus spur Benton to perform an unprecedented operation on the girl.

Corday faces M&M where the board was discussing the mistake that Corday made after she gave the wrong dosage to a patient. She decides to take the offensive and let the board know how wrong it is for her or any other doctor to work 36 hours. The board decides to do nothing about it, and she later decides to amicably end her relationship with Benton. At the hospital arrives Ruth Johnson who was born 100 years ago in that same hospital and shares some experiences with Carter. Carol is horrified by the truth behind a young boy's fatal shooting.

It's Christmas day in the ER. An 18-year-old boy arrives brain-dead, and Carter has to convince his parents to donate his organs, since a 16-year-old girl needs a liver. Benton risks his career by preventing Romano from operating under the influence. Ross and Hathaway have a religious dispute over how to deal with a pregnant 13-year-old. Corday is charmed by a musician who is facing surgery for prostate cancer. Dr. Lee flirts with Mark but turns out to have some major issues and strange story-telling habits.

Ross helps the mother of a dying boy; Benton attends a parent/child signing class. Corday doesn't give her account in the case against Dr. Romano. Romano blackmails Corday into dropping her support for Doyle's harassment lawsuit against Romano, but Kerry gets Romano to rewrite his insulting and inaccurate review of Doyle's job performance. The ER unites to help an injured woman who needs to find temporary homes for her many dogs as she gets treatment. Mark treats the hospital janitor, Mobalage, whose injuries suggest he has been tortured in the past. Carter discovers something with one of the med students he is mentoring.

Benton travels to a Mississippi clinic during his vacation time to earn money for his son's therapy, and becomes a local hero when he uses his medical knowledge to help several residents.

Carter deals with tenant drama at an apartment tower during a ride-along that later has deadly consequences, Lucy has to hide a cancer diagnosis from an ill woman at the behest of the patient's family, Carol finds out she is pregnant, Kerry reflects on her own family issues when an injured wrestler comes to the ER, and Greene continues to help Mobalage, who may be deported if he can't tell the INS about the abuse he suffered in Nigeria.

Greene uses a past trauma to help Mobalage save himself from deportation. Carter applies for chief resident and spends the day in charge of the ER, where he misunderstands a case involving the many broken bones of a baby, while Lucy begins her first psych rotation. Weaver may have found her biological mother, but defies a DNR order to find out for sure. Benton and Corday clash over a surgical fellowship.

Romano observes the ER, and rubs the staff the wrong way. Lucy finds out that an elderly patient's bedsore is really much more. Carter breaks up with his girlfriend. The power goes out at County General, and the doctors must keep critical patients alive. Corday investigates the rape of a comatose patient.

A recommendation from Weaver allows Jeanie to have temporary approval as a foster parent for baby Carlos. Reggie and Jeanie get married. Lucy and Kovac talk with a young woman whose husband they believe is very dangerous.

Kovac and Haleh take care of Hathaway's twins so the new mother can finally get some rest. The job transfer for Carla's husband does not get approved allowing Reese to stay in Chicago. Lucy endeavors to get a heart transplant for a young woman and goes to Romano's house begging him to perform the surgery.

Lucy's patient finally gets the call to receive a heart transplant, but there are complications. Greene interferes in a gay couple's domestic situation. Corday tricked her patient who murdered several women and now he's being transferred to a county jail.

Two boys brought in after a fight at school leads Cleo to discover that one of them has a number of bruises and infected wounds. Hathaway's obstetrics nurse, Abby Lockhart, joins the ER as a third year medical student on an ER rotation.

Dr. Greene and Dr. Corday bond with their parents, Lucy cares for a patient with a psychotic break, and Valentine's Day celebrations in the ER end tragically.

Carter and Lucy are discovered and the staff struggles to save them and go on with normal patient care.

As the result of a school shooting, Kovac and Benton care for the gunman and his victims. Abby discovers that Carter has been illegally injecting pain relievers. Greene and Weaver confront Carter about his problem, and Weaver orders him to enter a drug rehabilitation center or leave the hospital permanently.

A young couple cope with their baby being premature; Greene and Corday struggle with their relationship.

Benton is unable to find a job after Romano negatively influences local hospitals. He reluctantly agrees to accept Romano's demeaning offer of a per diem job at County with no benefits. Kovac and Abby are attacked by a mugger with a steel pipe. Injured, Kovac protects Abby and smashes the robber's head on the ground repeatedly.

Dr. Corday suggests a quick surgical procedure for a patient with back pain before taking off on a romantic weekend with Dr. Greene. Abby's mother, Maggie, unexpectedly visits the hospital and wreaks havoc on Abby's life. Dr. Chen needs the father of her baby to sign paperwork to go through with the adoption.

Mark Green is in New York on New Years eve for cancer surgery. Meanwhile a father and son are involved in a car crash.

Benton and Cleo clash over his deceased nephew's girlfriend. They finally agree to call a social worker. Benton confesses his love to Cleo. The spinal surgery malpractice suit is settled by employing a technicality: the equipment used was later recalled by the manufacturer. But Corday now doubts her abilities as a surgeon.

In the series' 150th episode, a massive train wreck mobilizes the emergency room doctors. Corday, Carter and Kovac rush to the scene. Corday falls and injures her back, bringing on contractions in only her 25th week of pregnancy. While amputating the legs of a fallen firefighter, Corday stops because of her pain.

A demented patient causes a shootout in the emergency room. After terrorizing people in the ER with a gun, she gets shot by a policeman. She soon dies. Benton later discover her dementia was caused by an aftereffect of his surgery that he and Cleo should have detected. Carter pursues a cute intern.

Maggie contests Abby's attempt to institutionalize her. Weaver treats a few bizarre patients. When Legaspi returns to work after being exonerated of sexual harassment, Weaver tries to reconcile with her. Benton injures his hand while transporting his former teacher to the hospital and must contend with the teacher's wisecracking elderly buddies (TOM BOSLEY and TOM POSTON).

Greene's daughter comes to live with him and Corday. Carter and Abby become more intimate. Chen must prove her skills while saving a baby. Weaver terminates Malucci after witnessing him having sex in an ambulance.

Dr. Susan Lewis arrives, looking for work in the Chicago area again. Greene hires her, over Weaver's objection. Chen nervously attends a risk management review, accompanied by the unforgiving Weaver, to discuss a patient who recently died under Chen's supervision.

Lewis faces a hectic first day back at County General. Benton and Roger become frantic when they can't locate Reese. Carter's grandmother is brought to the emergency room. Carter and Abby deal with inept medical students.

Corday's ordeal, caused by the recent infection-related deaths of several of her patients, worsens when she is closely observed by a stern taskmaster. Corday is outraged when a county investigator accuses her of deliberately euthanizing the patients, who all happened to be elderly.

Peter Benton continues his court fight against Reese's stepfather, Roger, who seems to have the upper hand. When a woman is accidentally shot during a gas station robbery, Dr. Corday tries to convince the husband to let them harvest her organs. A 15 year old boxer is brought in with a head trauma after sparring with his older brother. Newlyweds are having trouble when she constantly breaks out in a rash; Carter thinks he knows the cause. Luka tells Abby that he may marry Nicole, who has told him she is pregnant. Dr. Green lays down the law when the police bring in a high school student and he learns that his daughter is outside sitting in the police car.

Dr. Benton is awarded full custody and Roger receives visitation every other weekend.

Drs. Corday and Greene are awkward when working together in the ER. Dr. Weaver treats victims of an intense fire that may take the life of a dear friend.

When Dr. Lewis gets a hysterical call from her niece, Susie, she hurries to New York to search for the child and her sister Chloe.

Dr. Carter reads a letter from terminally ill Dr. Green to the ER staff. Dr. Weaver lashes out at a mentally challenged patient. A terminal, homeless man continues asking for Dr. Green.

Dr. Carter, Abby and other staff of the ER are quarantined as the CDC investigate a mysterious, deadly outbreak.

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

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 takes on a new med student for a surgical rotation - Paul Nathan, who suffers from Parkinson's disease and decided to pursue medicine after being diagnosed. Despite a difficult first day, both professionally and medically, Nathan makes a difficult diagnosis. Romano's rehab lags behind his expectations, and he begins to think his role in surgery is no longer an option. In a moment of personal weakness, he tries to express his feelings for Corday. Weaver continues to display erratic behavior, raising staff suspicions about her menopause. Luka's burgeoning sex addiction worsens, as an affair with Chuny is revealed, and tensions rise when he treats a patient with a perpetual erection.

Abby fears the worst when her brother Eric suddenly disappears. He is actually AWOL and she forges Carter's name to obtain his medical records. Carter and Chen treat a frightened Chinese immigrant nanny, Tong-Yi, whom they suspect was impregnated by her employer. Meanwhile, new surgical resident Paul Nathan, who is struggling to overcome a physical disability (Parkinson's disease), tries to help in the emergency room but his fellow doctors do not appreciate his advice to patients. Unable to quench his sexual appetite, Kovac also gets into trouble in his professional life, despite his admirable resolve to find an eye specialist to treat a young gunshot victim. Gallant and fellow medical student Erin Harkins engage in an escalating competition of medical knowledge. And Weaver gets some much-needed good news.

Abby's family nightmare continues as she searches for her missing brother Eric, who she suspects is suffering from serious mental problems. Gallant accompanies her to his military base where they find Maggie, whom Eric turned to for help. When he's transferred, Abby and Maggie go to a Midwestern air force base, hoping to prevent Eric from being court-martialed for being absent without leave. Carter struggles to get out of Chicago to join Abby. Meanwhile, Corday treats a family of patients who, while building a snowman, were severely injured after being struck by a truck driver. She must help the father, Stuart, make a life-or-death decision. Corday also sympathizes with troubled surgical resident Paul Nathan as he struggles with the increasing symptoms of his physical handicap.

Harkins faces a tough call while treating a troubled teen involved in a car crash with her dad; Abby races to stop Maggie from taking manic-depressive Eric out of treatment; and Kovac hits a new low when an elderly woman tips him for his medical services. Meanwhile, an abandoned baby dredges up painful memories for Chen; and Pratt goes to bat for Leon after he's fired from his job for stealing.

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

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. A baseball player gets treatment for a heart problem.

It's Greg Pratt's last shift at County General and he treats a number of cases that were started by John Carter on the day shift. They treat a 12 year-old near drowning victim who has little chance of recovery; a Buddhist nun who has a special gift of seeing another's inner self; a woman who is convinced that the day's solar eclipse signals the end of the world; a drug addict who scams both of them for pain medication; and a pregnant woman who had her baby torn out of her womb. Dr. Romano has his re-attached arm amputated. Carter receives a call from Luka Kovac asking if he can come to the Congo and help out. Abby is none too pleased. Meanwhile, Doc Magoo's burns to the ground.

Weaver rushes to the aid of her wife, Sandy Lopez, when the firefighter is severely injured while working and must now battle for her life. Frightened Weaver whispers hope to Sandy by reminding the victim of their newborn child.

A rape victim, barely able to speak, does all she can to help police find her attacker.

Pratt struggles to get a straight story when two abused boys come into the ER with their father. Two U.S. Army officers enter the ER.

Weaver, Kovac, and the other doctors work frantically to try to save Jerry and a pregnant Abby, who were both critically injured during the shootout that left the ER in shambles. Meanwhile, Sam tries to escape from her ex-boyfriend and his criminal accomplices as they head north, but things quickly turn violent.

Curtis Ames, a carpenter who suffered a stroke under Kovac's care, sues him for malpractice. Kovac and Ames square off in court as each man's recollections of Ames' treatment are recounted via testimony and flashbacks. Meanwhile, Abby returns to work and must adjust to the dramatic changes in her life, and Pratt's early morning trip to the barbershop results in a new awareness of community need. Also, Abby and Pratt try an unconventional method for treating a heart patient and Neela tries a risky procedure which doesn't sit well with her chief.

Kovac anxiously awaits the verdict between himself and Curtis Ames but fears the worst. Meanwhile, Neela disobeys her chief's orders and also questions her feelings for Gates, and Weaver unwittingly steals the spotlight from Morris in his big television debut.

It's Christmas in the ER. A homeless boy sends Gates and Ray on a mission. Meanwhile, in the ER, Neela oversees an unusual kidney transplant case; Sam takes a stand when a patient is dumped in an alley by another hospital; and Morris plays Santa for a special girl and learns the meaning of Christmas.

Weaver cares for a Katrina survivor who's reluctant to have surgery on her foot; budget cuts force Luka to make a difficult personnel decision. Also, Gates' home life intrudes on the ER; and Pratt and Hope are shaken after a patient in their care dies needlessly.

Abby and Sam try to treat an aspiring comedian with mysterious symptoms; Pratt must defend his actions in front of the medical board; Neela scrubs in on a kidney donor transplant; and Morris, as the lone attending, must run a busy ER. Also, Kovac gets a surprising proposal from Abby.

Kovac and Gates find themselves with a moral dilemma when a woman comes into the ER with acute liver failure; Neela finds herself questioning what is right when Manish decides to give up a kidney to a complete stranger. Meanwhile, Ray fights to get to the bottom of a cheerleader's accidental fall; Abby gets a prediction for her future; and Alex's troubles continue to intrude on Sam's work life.

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.

Gates and Julia nurture their newfound romance but are soon interrupted by a troubled phone call from Gates' ward, Sarah.

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

A young woman with a failing liver has a difficult reunion with her parents, whom she has not seen in six years. Abby receives a job offer. Brenner isn't nice to Laverne after they sleep together.

Neela experiences alternate versions of the same day.

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.