The season premiere offers multiple points-of-view of the same events a la Rashomon as Dr. Greene ministers to a sobbing young woman who was injured during a confrontational television talk show melee where she learned bitter family news -- but Greene has to face his own demons when a board of inquiry investigates the case of his serial killer patient. Meanwhile, a stoic Dr. Carter must attend a family funeral which reunites him with his detached rich parents. Dr. Benton keeps a watchful eye on the recovering Cleo while he deals with his grieving sister's attempts to cope with her teenaged son's death. A nervous Dr. Weaver returns from her African sabbatical and warily waits to see how her colleagues react.

Just when Dr. Carter thinks he's done for the day, the ER sucks him back in frenetic fashion as he is swamped with problematic patients -- including several heavy metal roadies and musicians after concert accidents -- while Dr. Benton is shocked to hear the full report when his young son is involved in a car accident. Newly appointed chief resident Chen panics when she is overwhelmed with patients -- one of whom she misdiagnoses -- while Dr. Weaver is suddenly AWOL on personal business just as several lives are in the balance. Meanwhile, Abby feels neglected by a distracted Dr. Kovac on an ugly night out, and she especially resents his flirty relationship with an attractive French waitress.

Dr. Greene is surprised when his rebellious teenaged daughter suddenly appears at the hospital after running away from his ex-wife while a skirt-chasing Dr. Malucci flirts with disaster and Dr. Carter and Abby draw even closer to each other. A hesitant Dr. Chen is tested when she struggles to save the life of an abandoned baby -- who some believe has a birthmark resembling a religious icon. A resourceful Malucci does some fast work when he tries to help an ailing patient while stuck together in a hospital elevator. Dr. Romano dresses down Dr. Weaver when a local newspaper investigates the death of a patient who expired on her watch.

Former County General alumna Dr. Susan Lewis returns to Chicago looking for a new job and swings by her old digs to renew friendships -- especially with Dr. Greene -- while a nervous Dr. Chen is accompanied by Dr. Weaver to a risk management review of her treatment of a deceased patient. Elsewhere, Dr. Benton is caught between a life-saving surgery and the need to pick up his young son before his school locks up. Dr. Corday meets Dr. Lewis and struggles with the parents of a young boy with a rare and chronic disease who have grown discouraged with his long-term prognosis. Dr. Kovac is surprised when a beautiful French waitress shows up in the ER and asks for him.

A wary Dr. Lewis returns to County General and clashes with Abby and others while her patients include a misunderstood Hispanic woman with seizures -- and Dr. Greene treats an injured man whose frantic daughter mistakenly crushed him with her car. Elsewhere, Lewis ministers to a man who is pretending to be comatose for a very good reason; Dr. Benton tries to leave the surgery room when he learns that his young son is missing; Dr. Carter is shocked to see his ailing grandmother brought to the hospital; Dr. Corday must adapt to co-habitating with Greene's teenaged daughter and is investigated when another patient dies of infection.

Dr. Corday's ordeal over the recent infectious deaths of several patients balloons when she is shadowed by a taskmaster who follows her to check for cleanliness while Dr. Lewis fields two college patients who are suddenly attacked by a fast and lethal virus. Elsewhere, Dr. Benton clashes with his toddler son's other father, Roger, over visitation rights; Dr. Kovac arranges for the ER to hire his friendly French barmaid as a runner with near-disastrous results; Abby flirts with a wounded fireman and Dr. Greene must referee between his self-indulgent 14-year-old daughter Rachel and his tense, fed-up wife Corday.

A brittle Dr. Corday desperately searches for a possible Angel of Death who's been secretly murdering her elderly patients -- leaving her to shoulder any possible blame -- while a pensive Dr. Benton reluctantly agrees to a paternity test to prove he's the real father of his son Reese. Elsewhere, Dr. Greene hardly shares a happy home with a stressed-out Corday and his wild teenaged daughter Rachel who now also courts trouble at school. Dr. Carter shares disappointing news with his ailing but headstrong grandmother, and he also joins Dr. Lewis in treating a young, self-abusing woman who's been cutting herself. A bright new and inquisitive first-year student makes all kinds of impressions on the curious staff. A resentful Abby nonetheless comforts new staffer Nicole after a traumatic event.

When a torrential rainstorm pounds Chicago, patients stack up while Dr. Weaver speeds to an accident site where a pregnant woman lies injured inside a wrecked ambulance while live power lines spark -- until heroic first-year resident Gallant makes a dangerous leap of faith. Elsewhere: a shaky Dr. Benton gets the lab reports that will determine if he is the father of his son Reese; Kovac's new girlfriend gets in trouble and gives him some unexpected news; Dr. Carter is shocked to see his grandmother wheeled in after breaking her hip in a hit-and-run car accident which injures a young woman -- and Dr. Greene tends to a guilt-ridden boy who feels responsible for the disappearance of his younger brother after playing in a flooded river.

Dr. Benton and his attorney begin a bare-knuckle fight in court to take custody of his young son from Roger -- the boy’s other father -- while Dr. Corday waits for a distraught husband to decide if surgeons can remove his terminally injured wife’s organs for transplant before time runs out. Elsewhere: Dr. Greene and Dr. Lewis treat a brain-damaged teenaged boxer who was hurt while sparring with his guilt-ridden brother; Dr. Weaver crosses paths again with a feisty firefighter who once helped her in the field; Dr. Carter tries to aid a young woman who complains of a nasty recurring allergic reaction; and Greene suspects the worst when the boyfriend of his rambunctious teenaged daughter Rachel tests positive for marijuana.

As December 25 nears, Dr. Benton boils over with rage and frustration as his custody trial for his son Reese hits a critical stage -- and he must choose between his ER job and the child unless the cranky Dr. Romano agrees to custom-tailor his work schedule. Elsewhere, a busy Dr. Carter finds romance, receives some jolting news from his father who's visiting for the holidays and then ministers to a boy whose fall from a tree causes great concern among his tight-knit family; Dr. Weaver is perplexed by a pregnant woman who's ready to deliver her baby despite remaining in a coma for a year; a sobbing young mother accidentally shoots her son near the Christmas tree, and a curious Abby spies Dr. Kovac's elusive French girlfriend sneaking through the hospital.

An embittered Abby tries to help a crying boy whose single mother died of a stroke and also tries to keep Dr. Carter distracted and away from Paul Sobriki -- the schizophrenic man who once stabbed him and killed a fellow doctor -- who checks into the ER for an injury after being released. Carter also has trouble at home when he clashes with his mother over the care administered to his grandmother as well as other festering family issues. Elsewhere: Abby is startled by news bulletins from both her ex-husband and Dr. Kovac; Dr. Greene confronts his rebellious daughter when he checks out her room and is later asked by a dying burn victim not to let his family see him in his condition; a wavering Dr. Weaver comes to a crossroads with her developing relationship with a firefighter; and Dr. Chen meets with Carter to discuss recently discovered evidence in the wrongful death case that resulted in her dismissal.

Dr. Lewis clashes with Dr. Weaver over the treatment of an injured and condemned murderer who wants to die in the ER rather than wait for his execution while Abby urges her battered next-door neighbor to seek shelter from her abusive husband. Elsewhere, Weaver has a trying day as she is embarrassed in front of her co-workers by her fiery firefighter girlfriend and she is also forced to re-hire the returning Dr. Chen who reveals damaging evidence that could put the blame on Weaver for a patient's accidental death. In addition: a weary Dr. Carter must mitigate between his warring parents as they plan their divorce and also diagnoses a wannabe rapper who tests positive for HIV -- but refuses to tell his naive girlfriend; Dr. Greene tries to help a guilt-stricken father who suffers a heart attack on the day his estranged daughter is to be married, while on the home front, the doctor struggles to find any common ground with his wayward 14-year-old daughter.

Drs. Greene and Corday are gripped with fear when their helpless baby daughter is brought in with an accidental overdose -- while Dr. Lewis treats a father and daughter who were injured after opening an exploding letter bomb. Meanwhile, Dr. Weaver seethes when Dr. Romano hands off some of her many duties to Lewis and Dr. Carter meets a dying 12-year-old leukemia patient that his charity-minded mother brought in. Elsewhere: the doctors marvel over a 13-year-old girl who crashed her car while trying to drive her drunken mother home; Dr. Gallant takes pity on a sickly bum and his friendly mutt Stinky; and Abby gets a desperate, late-night visit from her female next-door neighbor.

While their baby daughter continues to fight for her life, Dr. Greene has sharp words with his wife, Dr. Corday, after she orders Rachel out of their home while Abby might regret championing a battered female neighbor who refuses to press charges against her abusive husband. Elsewhere, some bad munchies soon have everyone scurrying for the bathroom as Kovac returns to help out a short-handed staff. In addition: Dr. Carter confronts his mother over issues of emotional abandonment and gets a surprise visit from his father; the ER team treats an elderly polar bear swimmer with heart problems; a fearful 15-year-old girl with vaginal bleeding, and a recent lottery winner who's unlucky enough to have been stabbed by a falling icicle; a diminutive lap dancer who accidentally swallows a customer's wedding ring.

A lonely Dr. Greene faces an uphill struggle for survival and his pain is intensified when the angry Dr. Corday keeps his recovering infant daughter away from him, so he busies himself in the ER treating a father who severely burned himself while experimenting with illegal drugs. While the victim's life is in immediate jeopardy, Greene is further tormented by the man's request not to let his family see him in his horrific condition. Elsewhere: Dr. Chen is confronted with a teenaged comatose patient who confounds her mother when it's discovered that she is pregnant and ready to give birth; a little girl arrives at the ER with her father who suffers from critical gunshot wounds; a teenager is banged-up when his father gets careless with a careening snowmobile; Abby fumes when the man who beat her is released -- and moves back in next door; the returning Jerry clashes with fellow desk jockey Frank.

In a dramatic change-of-pace episode, after a bout of horseplay following a dominatrix’ appearance in the ER, Dr. Weaver orders Abby, Dr. Carter, Dr. Lewis, Dr. Kovac and Dr. Gallant into a day-long sexual harassment seminar -- which unleashes a torrent of truth about their mutual relationships. While the class is delayed for a tardy instructor, the five share intimate details while alternately mocking and challenging each other -- especially with the thorny romantic attractions involving Abby and Lewis with Carter. What’s more, Carter and Kovac kill time by engaging in a roughhouse round of fencing that speaks volumes about their contending interest in Abby.

Drs. Corday and Greene continue to awkwardly bump into each other in the ER while Dr. Weaver treats victims of a raging inferno -- one that might have cost the life of her intimate firefighter friend. While Corday suspects her husband is romantically involved with Dr. Lewis, Greene is stumped when he asks the reluctant sister of a severely ill woman to donate part of her liver that would save her sister's life. In addition: Greene chastises the adoptive parents of an uncommunicative young boy who almost dies after experimental therapy; Dr. Chen is shadowed by a disturbed man who is the victim of severe psychological trauma; the doctors react to several college coeds after they are attacked on campus by a madman; a couple of senior citizen adulterers are busted in the ER.

While Dr. Greene tries to immerse himself in his work, he reluctantly discovers that his aggressive illness is hampering his coordination -- and watching other end-stage patients struggle with their treatments has a sobering effect on him. Elsewhere: Greene has a poignant reunion with his ex-wife and later mediates between the staff and a stubborn but deluded homeless man; Dr. Pratt, a self-confident new intern, gets some advice from Greene about his bedside manner; Abby can move out of Dr. Kovac's apartment when her abusive neighbor moves away; Greene treats a family man who receives the worst kind of news; an Egyptologist is hospitalized for a rare disease; confusion over an elderly woman's wishes results in heroic measures to resuscitate her.

Dr. Lewis is frightened when she receives a traumatic call for help from her 6-year-old niece in New York and she rushes East to search for the child and her trouble-prone sister, where she enlists the aid of Officers Yokas and Bosco from NBC's Peabody Award-winning Third Watch to comb the mean streets. Elsewhere: Dr. Corday fears the worst when she is phoned by Dr. Greene's teenaged daughter in Hawaii where the pair are vacationing; arrogant newcomer Dr. Pratt causes havoc and clashes with the staff when he tries a dangerous unauthorized procedure on a dying patient; Dr. Carter chastises Dr. Kovac for allowing Abby to slip back into using alcohol as a crutch, and Dr. Weaver contends with a crushed couple who can't decide if they want to disconnect their brain-dead son's life support.

Dr. Carter reads a letter from the ailing Dr. Greene to the E.R. staff. Meanwhile, Dr. Weaver lashes out at a mentally challenged patient; Carter feels helpless when a terminally ill homeless man continues to ask for Greene's help; and Carter tries to coax a tipsy Abby to attend an Alcoholics' Anonymous meeting with him. Elsewhere: the obnoxious Dr. Pratt learns that he will be assigned to County General for his residency; and Dr. Romano struggles to save a young girl's life after an auto accident reveals a dangerous malignancy.

In an affecting and poignant look at Mark Greene's final days, the once driven E.R. doctor takes reluctant Rachel to his childhood home in Hawaii. There he indulges in life's simple pleasures and tries to impart bittersweet memories and family history to his distant daughter. But as their clashes escalate -- and as Greene's health fades -- so does the chance for a final reconciliation between them.

Fear grips Chicago when Carter and Abby treat two children with ominous symptoms that force the E.R. into quarantine until federal disease experts arrive. As Carter fights to save the youths, the staff is trapped with the suffering patients and a busload of injured and ornery senior citizens. Media swarm the hospital and riot police guard the exits while the restless victims begin a small riot in an attempt to escape the dangerous and stifling conditions inside. Meanwhile, Drs. Pratt and Chen -- who may have contracted the disease -- put aside their own symptoms as they labor to save the life of frequent homeless visitor Stan the Can.