An out-of-control truck barely misses a very pregnant Hathaway but cuts a wide swath of heavy casualties who flow into the ER, taxing the collective abilities of everyone on shift. Dr. Carter unexpectedly treats the older and attractive ex-wife of his cousin with unexpected repercussions. Drs. Greene and Weaver plot strategy when they hear rumors that the combative Dr. Romano might be named as the new chief of staff. Dr. Benton must maneuver quickly during a mediation hearing if he is to prevent his ex-girlfriend Carla from leaving the country with his infant son. Elsewhere, Luka Kovac, a doctor from Eastern Europe who moonlights in the ER, and Dr. Cleo Finch, a second-year resident in emergency medicine and pediatrics, both reveal a talent for handling hurting children.

Still reeling from his latest family crisis, Dr. Greene clashes with Dr. Weaver over the continuing treatment of a critically ill teenager who changes her mind about her do not resuscitate agreement. Hathaway ministers to an old widow who has no one to turn to in her last hours. Dr. Carter stumbles into a turf battle with paramedics when he and a new hotshot doctor rush out to help a construction worker who is critically injured just a block away. Dr. Benton parleys with a court-appointed therapist as he tries to stop his ex-girlfriend from moving to Europe with his son. Carter's new friend Elaine visits the hospital again. Jeanie cannot resist taking a special interest in an HIV-positive baby who is virtually parentless. Dr. Corday gets an offer from Dr. Romano that she cannot refuse.

Dr. Greene sees red when he encounters Dr. Lawrence, a newly hired attending physician who is considered a legend in emergency medicine, whose confident ease irritates Greene immensely. Gunfire breaks out in the ER when a gunshot victim identifies his assailant. Dr. Carter tries unsuccessfully to console a family friend. Dr. Finch disagrees with the doctor of a child involved in an auto accident who wants to discharge the boy immediately. Jeanie counts down the hours until her marriage and gets a pleasant surprise among her wedding gifts. Dr. Romano sticks Dr. Corday with shepherding an inquisitive newspaper reporter who is preparing a profile on him. Dr. Benton tries to ignore some disturbing news about his son. Moonlighting Dr. Kovac lobbies to put a husband under psychiatric custody when he suspects that the man has been beating his wife.

Cleo diagnoses a bratty little girl with food poisoning and is shocked when she reappears with more severe symptoms. An annoyed Dr. Greene tries to help his father sort out his insurance problems via long-distance phone calls when the old man runs his car into a tree, while Greene and the likable Dr. Malucci treat a skydiving victim and a distraught teenager who tried to hang himself. Dr. Lawrence -- always ready with an opinion on any case -- argues with the nurses over his prescribed medication for another skydiving patient. Dr. Carter arranges to see recovering patient Elaine Nichols again. A sympathetic Hathaway coaxes a pregnant but uninsured waitress to come to the ER for an exam. As chief of staff, Dr. Romano orders Dr. Corday to do his dirty work and is not happy with an unflattering, tabloid-like newspaper story about one chaotic day in the life of the hospital's ER.

An explosion during a high school science class floods the ER with a variety of burned, gassed and broken patients. Dr. Greene rescues Dr. Carter from one student's irate father. Hathaway urges a young pregnant waitress to enter a drug rehabilitation program while Lucy also pleads with an artistic painter to do the same. Dr. Benton tries to protect a young man who learns he's HIV-positive while donating blood for his injured brother. Carter wonders if he's gotten the final brushoff from Elaine. Jeanie is distracted at work over her young adopted son's wheezing back at home. An inquisitive Malucci courts trouble when he solicits information about Dr. Weaver's disabled leg.

Hathaway can't resist trying to help a fellow single pregnant woman who refuses to quit her unhealthy lifestyle and seems resigned to her fate, while Dr. Weaver questions the work of her former mentor, Dr. Lawrence. Dr. Benton agonizes over taking a self-administered paternity test that will determine if he really is the father of his toddler son. Dr. Finch is blamed for an explosion in the suture room but Dr. Malucci might have a different answer. After a nursing home fire, Dr. Carter is chastised for not convincing a frightened older woman to sign a consent form that would let her terminally ill husband die. Later, Carter is torn when a poor father asks him not to report that his son has diabetes until his worker's insurance kicks in, and after hours, he visits the moody Elaine. Elsewhere: a beaming Jeanie has startling news for Weaver, and a new desk clerk overcomes a rough beginning to his day and soon has the staff in stitches with his comic impressions.

A heroic Dr. Corday works hard to salvage the life of a known carjacker and kidnapper while nearby Drs. Weaver and Kovac strain to sustain his sexually assaulted victim who is desperate for the right kind of blood transfusion. Cleo overrules Lucy and orders toxicity tests for a 15-year-old boy and her hunch pays off. In addition, Lucy regrets her decision to allow an elderly gospel group leader with chest pains, to leave for a performance. A moody and pregnant Hathaway's dull day answering phones suddenly takes a dramatic twist, and she later visits a drug-abusive new mother. Dr. Carter eagerly takes on more responsibility in the ER from Weaver. Dr. Greene has no clue about the whereabouts of his visiting father when the older man doesn't show up at the airport for their Thanksgiving together. Dr. Lawrence receives counseling for his embarrassing medical condition but still shows flashes of brilliance.

A snowy Thanksgiving turns chaotic for Hathaway when she suddenly goes into labor on the subway and fights just to get to the ER -- where the real harrowing battle begins to save her premature twins with the help of an obstetrics nurse. At the same time, Hathaway's Lamaze mate, Dr. Greene, is unaware of her plight as he brings his precocious daughter and his cantankerous visiting dad over to Dr. Corday's for a traditionally dysfunctional holiday dinner. When Greene is notified of Hathaway's situation, he leaves poor Corday with his two relatives who each encounter a personal crisis. Dr. Malucci impresses Dr. Carter with his knowledge of a rare affliction.

On Christmas Eve, a stubborn Lucy tries everything to help a desperate young woman, who is running out of time, get a life-saving heart transplant. A festive Dr. Carter, decked-out as Santa Claus, aids a wounded gangbanger and then offers to trade a gift for his gun, which prompts a flood of other gang members willing to trade their gats for choice presents. Dr. Finch regretfully ruins a dysfunctional family's holiday when she places Chad Kottmeier, a besotted teenager whom she previously treated, in the hospital's alcohol treatment program for his own safety. Hathaway gets help from kindly Dr. Kovac when she suspects that one of her four-week old twins might have a fever. An uneasy Dr. Corday must continue to treat a repulsive murder suspect; Dr. Weaver is shown some glitches in the ER's computer that was rated Y2K compliant; Dr. Benton receives shocking news from an angry Carla; and the ER swarms with sickly Santas.

Former emergency room resident Jing-Mei Chen -- once known as Deb Chen -- returns to resume her career in medicine and immediately makes an impact when she treats a runaway teenaged girl who bitterly keeps her identity secret. Elsewhere, Dr. Corday is asked to coax an injured murderer to confess the whereabouts of a woman's body -- to better give her family some peace of mind. The energetic Dr. Malucci tries to fix Dr. Weaver's car while he later discovers that a child hockey player suffering from shortness of breath has a more serious complication than first thought. Dr. Finch reconsiders discharging a talented teenaged athlete who's exhausted by her unrelenting practice schedule and need to satisfy her parents. Dr. Kovac sympathizes over two scruffy teenage brothers -- one developmentally disabled -- who would rather remain on the street than be separated by social services. Dr. Greene bails out of the ER when he learns that his stubborn father ran off from his San Diego retirement home.

A simple water shutoff makes the struggle for life even harder in the ER while Lucy is excited for Valerie, a patient she befriended who finally can receive a new heart -- if she can circumvent some last-minute medical complications. Drs. Carter and Chen duel over admitting an elderly patient with Parkinson's whose daughter pleads exhaustion in caring for her. Dr. Greene also is weary of lodging his troublesome father as he deals with the return of Nurse Hathaway, who is experiencing post-partum depression. Later, Greene treats a patient for seizures and suspects that his boyfriend is physically abusing him. Dr. Corday confronts the murderer whose life she saved before he is taken to county jail. In addition, Dr. Benton makes a tentative offer to Dr. Finch, Hathaway soothes a nervous boy with a broken leg and Dr. Malucci personally checks out a Hispanic pharmacy that also serves as an illegal back-door health clinic.

New medical student Abby Lockhart, the obstetrics nurse who helped deliver Nurse Hathaway's twins, has a chaotic first day when she joins the ER and is spat upon and bitten by a drug-addled teenage wrestler and misdiagnoses a hypochondriac. Dr. Corday grits her teeth when her haughty mother alights in town. Elsewhere, as a flu epidemic sweeps through the ER, Dr. Benton's promise to secure plastic surgery for a badly mauled little girl is in jeopardy and he later uses an unusual procedure to clear an airway on a patient with internal bleeding. Dr. Carter treats a bitter teenager with muscular dystrophy. Lucy tries to make an elderly patient with congestive heart failure comfortable in his last hours.

As Valentine's Day nears, Dr. Corday holds her breath when her domineering mother and surgeon wants to observe her at work in the hospital, while Lucy cares for a combative young law student whose headaches and erratic behavior might indicate schizophrenia. Competitive medical students Chen and Malucci jockey for first position but their increasing rivalry only hurts their patients, including a senior doctor with a dangerous tumor. Following a severe traffic accident, Drs. Finch, Kovac and Benton hope to save the lives of the parents of two quaking children who fear the worst. An elderly woman who lost her husband a few months earlier in the ER returns with a serious case of infection.

Valentine's Day arrives as the emergency room staff whirls into action on all fronts as they work heroically on two patients who suffered trauma. Even Drs. Greene and Corday are called from home to help. Meanwhile, the police begin an investigation into criminal activity inside the hospital and begin searching for a missing patient.

An off-duty Dr. Kovac witnesses a hit-and-run accident that leaves a young girl fighting for her life but he second-guesses himself when he elects to transport her to the hospital himself rather than wait for the paramedics -- and wonders if his desperate measures might ultimately kill her. Nurse Hathaway discovers that a promiscuous 14-year-old schoolgirl has cervical cancer and is torn when the frightened teen refuses to tell her parents. Drs. Greene and Corday react differently when they discover that their parents are getting to know each other very well. New medical student Abby disagrees with Dr. Weaver's quick assessment of a sick patient. Dr. Greene learns some sobering news from a patient's x-rays.

In pain, Dr. Carter hobbles back on crutches into the ER for the first time since his life-threatening attack and treats an overdosed suicidal patient with a controversial new procedure while a besieged Dr. Greene tries to take charge of a chaotic shift. Among Greene's runaway problems are his cantankerous father who resists treatment for his lung cancer, a poisonous Gila monster lizard on the loose and a non-stop torrent of complicated cases, one of which concerns his girlfriend Dr. Corday's well-meaning attempt to keep a brain-dead accident victim alive long enough to secure permission to harvest his organs. Elsewhere, Abby is devastated when she makes a simple mistake that could cost a terminally ill cancer patient what little time he has left; Dr. Chen is distracted by a hunky nurse who helps out in between receiving treatment for his own fainting spells; amid the uproar, Hathaway is interrupted by her nanny's calls regarding her crying twins; and Dr. Benton and Dr. Finch enjoy a sensual game of pool.

Dr. Kovac is unsettled about his responsibility to disqualify a series of patients with kidney failure when a precious donor organ becomes available, especially when one prospect is unaware that she's pregnant -- and must choose between the baby or the transplant operation. A few feet away, Dr. Romano decides to mix it up for a day in the ER trenches and clashes with two angry motorists as well as Dr. Weaver over proper treatment of a terminally ill pneumonia patient. Dr. Carter must do some fast-talking when a former patient, a diabetic young boy whose father previously had no insurance, reappears with dangerous symptoms. Drs. Finch and Benton are dressed down by Romano when a pharmacy misreads their scribbled prescription and issues a drug that nearly kills a constipated patient. Dr. Greene gets angry when Dr. Corday conspires with his crotchety father to place the senior Greene in a hospice.

Ex-lovers Dr. Benton and a testy Dr. Corday clash when Benton's current interest, Dr. Finch, asks him to overrule Corday for surgery on a young boy who may have suffered internal injuries in a car crash. Abby takes a big risk when she advises an exhausted pregnant wife with five children to undergo an abortion procedure against the wishes of her unsuspecting husband. Elsewhere, Dr. Greene must intimately care at home for his crotchety but humiliated father after the terminally ill man chases away his latest nurse. Dr. Carter reacts harshly to one patient, offers a misplaced diagnosis to another and later offends Dr. Chen when they try to save a young girl. Dr. Romano assumes personal command of the ER and displays his typically obnoxious charm.

Abby plays with fire when she intercedes on behalf of a sick young girl who needs a bone marrow transplant -- but the most eligible donor is her half-sister whose divorced mother refuses to okay the procedure out of spite for the girl's father who's her ex-husband. In another family, Dr. Greene admits his pneumonia-ridden father into the hospital and shares a rare but memorable father-son moment as the older man's time begins to wind down. Dr. Kovac gallantly offers to help Nurse Hathaway buy a used car and they enjoy their spring day on the town. Likewise, a daytripping Dr. Benton takes Dr. Finch out to Los Angeles to visit his toddler son and meet his sister Jackie who can't help but interrogate her guest. Dr. Carter is tormented by visions of his recent brush with death and draws Dr. Weaver's concern upon her return.

A weary Dr. Greene remains at home to care for his father and shares a tender moment, while a robust Dr. Kovac tries to court Nurse Hathaway. In addition, faulty hospital procedure causes Dr. Benton to assail Kovac for not checking up on a patient who now might lose his leg; likewise, Dr. Chen is horrified to learn that a simple metabolic test for infants could have prevented a boy's disabling brain seizure. Dr. Carter assumes Greene's shift and is a whirling dervish of activity who can't resist taking over other doctors' cases as well. When an anemic teenager refuses crucial treatment, Dr. Corday makes a calculated gamble in order to assist her. Dr. Malucci is enraged when a 6-year-old car accident victim claims that her father has been sexually abusing her.

A wound-up Dr. Weaver goes on the warpath when she encounters sloppiness, incorrect diagnoses and improper procedures among the ER staff, and Nurse Hathaway, Dr. Malucci and Abby all feel the heat of her wrath. A disobeying Hathaway earns Weaver's enmity when she revives a do not resuscitate cancer victim so that the patient can spend one last conscious moment with her young family while she ponders her response to Dr. Kovac's romantic interest -- and she makes a life-changing decision. When he's not goofing off, Malucci also gets an earful from Dr. Corday, who offers a sobering assessment of his performance. Dr. Greene re-thinks his father's burial request and determines to spend more time with his daughter Rachel.

Dr. Kovac crosses swords with Benton over prioritizing care for a young victim of a deadly school shooting versus a more seriously wounded gunman. Benton and Dr. Corday share a moment of mutual triumph when they successfully complete a risky but life-saving surgical procedure on a wounded student from the schoolyard. Kovac's draining day continues when he attempts to browbeat a teenaged stabbing victim into allowing him to birth her unwanted and unborn baby despite her adamant wishes to let the child die. A combative Dr. Carter is confronted by Dr. Greene and the other ER doctors over his behavior since being attacked. Greene tries to convince a hardy rugby player that his injuries are more serious than he thinks.