Greene percebe que o seu futuro médico está com seus dias contados; uma viciada entra em trabalho de parto; um trabalhador de um museu pega uma doença rara; e Corday precisa fazer as vontades de um paciente terminal para que possa morrer com dignidade.

Susan vai à Nova Iorque à procura de sua irmã e deu seu sobrinho; Carter discute com Abby sobre o seu problema com a bebida; Corday recebe notícias ruins de Mark no Havaí; e o orgulho de Pratt coloca Gallant e um paciente em perigo.

Carter confronta Abby sobre o seu problema com a bebida, por causa de uma carta de Mark; Kerry faz uma avaliação sobre a sua saúde; um acidente de carro revela um segredo sobre um jovem paciente de Lewis; e Pratt fica sabendo aonde passará o seu estágio.

Carter, Abby e outros permanecem em quarentena por causa de uma crise de varíola. Enquanto isso, Corday, em luto, volta para a sua casa em Londres, onde é criticada pelos seus hábitos americanizados.

O isolamento do pronto-socorro causa danos, mas Carter tenta manter tudo sob controle; Kerry incomoda Corday que ainda está de luto; por não seguir ordens, Pratt causa uma tragédia; e uma namorada paga o preço pela vida criminosa de seu namorado.

Quando um paciente usa a violência para resolver uma situação, Carter precisa tomar uma decisão drástica; Gallante lida com um hipocondríaco; Pratt mantêm um segredo sobre a sua situação domiciliar e Kovak enfrenta uma ex-amante infeliz.

Gallant tenta lutar pelos direitos de um paciente; Abby conversa com Carter sobre o seu problema com a bebida; Kovac consola a mãe de uma criança doente um pouco demais; e Kerry mostra sinais de desgaste durante a sua estreia, quase trágica, na TV.

A equipe trata das vítimas de um incêndio em uma festa do Dia das Bruxas; Nathan revela um segredo que coloca o seu lugar na rotação cirúrgica em perigo; e Weaver luta para salvar a vida de um bebê que teve um nascimento caseiro que deu errado.

Enfermeiras e médicos se desentendem por causa de Luka e o pronto-socorro sofre as consequências; o irmão de Abby retorna; Chen lida com um paciente violento; e Nathan consegue convencer um paciente terminal a não desistir de sua vida.

Kerry espalha as boas novas, enquanto Abby fica sabendo que seu irmão deixou o exército; Kovaca satisfaz os seus instintos; Corday e Nathan chegam a um impasse sobre a sua carreira; e Chen ajuda um paciente Chinês que está sendo explorado por seu patrão.

Abby vai até a Força Aérea de Nebraska a procura de seu irmão e se reencontra com a sua mãe; e uma tempestade de neve ameaça a tentativa de Nathan e Corday de salvar o que restou de uma família vítima de um motorista embriagado.

Harkins lida com um adolescente que sofre um acidente com o carro de seu pai; Abby quer evitar que sua mãe cancele o tratamento de Eric; Kovac recebe gorjeta pelo tratamento que dá a uma senhora; e Chen revive momentos dolorosos de seu passado.

As festas de final de ano terminam em um escândalo amoroso, um acidente fatal e um erro de diagnóstico. Enquanto isso, vítimas natalinas inundam o plantão, tais como dois duendes violentos, e vítimas de uma briga durante uma encenação religiosa.

Luka paga o preço pelo erro de diagnóstico que deixou um paciente com lesão cerebral; Carter se intromete na vida de Pratt quando ele é pego com uma arma; e Lewis quer que o departamento psiquiátrico preste atenção à depressão de um de seus pacientes.

Kerry concorda em esconder a doença sexualmente transmissível de um político; Pratt ignora os pedidos de uma mãe, prestes a morrer, em relação aos seus filhos; e a fortuna da família de Carter falha em pagar por um médico que chefia uma clínica gratuita.

Carter que salvar um médico necessitado; Pratt lida com um ladrão, amigo de Leon, e o policial em quem ele atirou; Corday lida com um novo cirurgião; e Romano coloca seu emprego em perigo, ao supervisionar uma operação a qual ele não pode terminar.

A queda de um avião mexe com o mundo de Abby; a carreira cirúrgica de Romano é alterada para sempre, um adolescente é suspeito de intencionalmente atropelar seus colegas; e Pratt tem uma reação inesperada com a revelação de Chen sobre seu bebê.

Com a ajuda de Carter, Abby continua a procurar por seu irmão; Enquanto isso, o Kovac volta ao trabalho e lida com um caso de overdose; Pratt cava um buraco ainda maior com Chen, durante o seu trabalho com os paramédicos.

Três pessoas são assassinadas durante um assalto ao Doc Magoo, mas Chen consegue identificar um dos suspeitos; Lewis faz amizade com uma jovem paciente de câncer, apesar de sua mãe não aceitar; e Carter pede Abby em casamento.

Kerry faz um favor para um político homossexual não assumido, mas sofre as consequências; Kovac encontra uma saída para seus problemas; e os dias de chefe de Romano estão contados.

Romano sai do pronto-socorro; uma gestante recebe notícias tristes sobre a sua saúde; Pratt estraga o aniversário de Chen; Luka quer ajudar uma criança cujo estado de saúde é crítico; e um paciente causa uma mudança na vida de uma pessoa na equipe.

Weaver cuida de um bebê de 6 semanas; Lewis trabalha com um paciente com problemas mentais; e um médico da Croácia supervisiona a cirurgia cardíaca em um jovem menino.

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.

Um eclipse faz com que membros de uma seita tentem cometer um suicídio coletivo e as vítimas são enviadas ao pronto-socorro; Carter e Pratt reconsiderem o seu futuro na medicina; e uma gestante é vítima de um crime hediondo.

Carter se junta a Kovac na África, e os dois médicos lutam em uma batalha para trazer a cura para uma aldeia devastada pela guerra. Essa experiência fará com que eles ganhem um novo respeito por suas vidas, ao voltarem para casa.

Carter returns from Africa, going straight to Abby's bedside. Her response to seeing him is to ask for her key back. She is very chilly towards him all day until new med student Neela Rasgotra answers a phone call for Carter. The message: Luka is dead. Carter decides to go back to the Congo to bring the body back. Neela has a tough first day in the ER, earning Chen's ire after Pratt flirts with her. Gallant, now a full-fledged doctor, helps to show her the ropes.

Após receber um telefonema de Kovac, Carter retorna para África, mas não consegue encontrar a verdade, mesmo com a ajuda de um voluntário da Cruz Vermelha. Enquanto isso, alguns flashbacks revelam o destino do exílio do croata.

Luka Kovac arrives safely at County General and is hospitalized for treatment. His friend Gillian delivers John Carter's letter to Abby.

Pratt e Weaver discutem; Coop prova que é bom no que faz quando ajuda um paciente que sofre de uma doença misteriosa; Corday não consegue se adaptar à sua nova vida sexual; e Neela toma conta de uma menina que chegou ao hospital com sua avó inconsciente.

Um arquiteto sofre perda de visão e incomoda Lewis; uma mãe alcoólica reage de uma forma sinistra à perda da guarda de seus filhos; uma nova enfermeira chega ao hospital; e Abby faz uma mudança em sua carreira.

Pratt and Kovac clash over a miscarriage-prone young woman, Denny, who arrives to deliver a premature baby. Pratt wants to make heroic efforts to save the unborn child, while Kovac is adamantly against spending vast amounts of money to keep the forever sickly baby alive.

To everyone's amazement, Lewis makes a date to share a home-cooked dinner with the elderly Ben Hollander, her depressed patient who is going blind.

On Thanksgiving Day, a helicopter crash outside the ER leaves several injured, and kills Dr. Romano. Alex tries to bring Sam and Luka together.

Neela helps treat two Amish teens who were in a car crash. Sam argues with Dr. Kovac when he pays too much attention to her son.

Dr. Carter celebrates Christmas at a clinic in the Congo dealing with low supplies and anti-Americanism, but in the meantime, falling for an AIDS worker named Makemba.

Carter returns to County General to hearty welcomes. Although Abby is shocked to learn that Carter's beautiful African girlfriend, Kem, is already pregnant with Carter's child, Abby has moved on with her life as well, going back to medical school.

Abby and Neela are assigned to a month-long rotation in the neonatal intensive care unit where they experience emotional roller coasters while caring for the sick infants.

Dr. Carter's girlfriend makes an impression as she observes ER operations. Dr. Gallant is almost shot during a domestic incident. Dr. Weaver dedicates a center to the memory of Dr. Romano.

Sam treats an abused, pregnant teen. Dr. Carter introduces African girlfriend Makemba to wintertime. ER chaos shocks a risk-assessment expert. Dr. Pratt and Abby restrain a man who has tuberculosis.

Carter misses his pregnant girlfriend who has returned to Africa. A family of four is rushed to the emergency room after suffering carbon monoxide poisoning from their faulty furnace--forcing the claustrophobic Neela to accompany a newborn baby into an extremely uncomfortable hyperbaric chamber.

Morris streets a patient without getting a psych consult, and the guy steals a tank and heads for County. Gillian is visiting Luka, and Sam's not happy about it. Luka and Sam make up by the end of the day though. A 13-year-old boy has chlamydia. Frank has a heart attack. Corday plays the dating game, going out with two men.

Carter sticks up for Neela when the other attendings doubt her future in the ER. Neela caves to the pressure and accidentally gives a patient the wrong medication. Gallant takes the blame for her though. Sam and Luka try to plan Alex's birthday party. Frank visits on his way to therapy. Chen's home nurse quits after her dad behaves poorly.

Weaver rushes to the aid of her female life partner, 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.

Pratt struggles to diagnose a woman who suffers mysterious chronic seizures. An attractive woman, Campbell, informally accuses flirtatious Pratt of sexual harassment. Abby ponders how to get her contentious patients' attention during her psychiatric department rotation.

A panic-stricken Weaver is ordered to give her son to the Lopez family. Carter greets the returning Kem, but their meeting with his father, Jack, gets tense after Carter announces plans for his grandmother's estate.

Carter takes Kem to the hospital to check on their baby since it's not kicking anymore.

Kovacs stops to help a woman and her son whose car broke down. Steve is getting close to Alex, and Sam panics. Abby is looking for her letter whether to see she passed her boards. Pratt shows off his new Chrysler. Elgin tries to build a connection between him and Pratt. Jing-Mei might be battered by her senile father.

After being shot at, Pratt, Jing-Mei and Elgin are trying to get of their sinking car. Sam took Alex with her while fleeing for Steve, Kovac is considering to go after them. Abby wants to go to bed since tomorrow is her first day as a doctor, but is thwarted by Weaver, whose custody battle might take a dramatic turn. A young drug-dealer is brought in with "a foreign object" in her tunnel of life.

Neela is still struggling with her decision not to continue becoming a doctor. We discover that Ray is in a band. Kovac and Sam are amoureux, but where does that leave them?

It's a busy Fourth of July and Carter is the only attending working.

Carter, Pratt, Kovac and Abby are dealing with a woman and her three children who've jumped from a three floor apartment trying to escape from the father. Meanwhile Dr. Lewis becomes Chief of Emergency Medicine, Howard quits his internship and Dr. Corday is facing dismissal.

Neela starts a new job in the emergency room after working at the convenience store near the hospital. On Neela's first day, Pratt expects the interns, Abby, Ray and Neela, to take on a large patient load during their shifts. Pratt turns processing the patients into a competition, in which Ray is clearly going to be the winner.

The last 44 minutes of ex-con & alcoholic Charlie Metcalf's life are in the ER, as he slowly succumbs to end-stage liver failure.

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

A wounded police officer's teenage son must make a life or death decision. Abby tries to convince a girl needing appendicitis surgery to stay at County, but her fathers wants her transferred to another hospital.

Abby has a dialysis patient in critical condition, but she cannot find his physician, who does not want to be bothered during the holidays.

Gang members kidnap Abby hoping she can save one of their members with a gunshot wound. Ray starts treating a patient, but when she requests a new doctor, he gets offended.

Two teens enter the ER with gunshot wounds. When one dies, Neela botches telling the next of kin, making the woman hysterical.

When a 16-year-old girl who had received a kidney transplant from her father arrives at the emergency room feeling dizzy, Carter traces the problem to a new drug that the girl was taking to control seizures related to her kidney dysfunction.

While examining a young boy, Pratt finds a suspicious gash across his chest and calls Wendall (recurring guest star MäDCHEN AMICK) for a consult. Kovac and Pratt examine a man who was shot when he confronted his boss with a gun. Jake (recurring guest star EION BAILEY) tries to convince Abby to date him despite his being a student.

Dr. Weaver meets her birth mother, but their relationship changes when Kerrie reveals she is gay. Dr. Carter causes a commotion when he confronts a couple hoping to scam some painkillers.

A soccer mom finds herself completely aware of everything going on around her, but is unable to move or speak after suffering a stroke.

Neela (who's in Chicago) and Gallant (who's in Iraq) miss each other and write letters. Gallant also tries to save the life of a little girl.

Sam's ex-husband shows up and wants to take Alex on a trip. Gallant is back and Neela hopes to see him before he goes back to Iraq.

A woman on a hunger strike refuses treatment until the INS give her son another deportation hearing. Abby searches for proof when she suspects a patient is the victim of elder abuse.

Jules 'Ruby' Rubadoux is back in the ER. He's still angry with Carter about the death of his wife.

Morris is named the new chief resident, which makes nobody really happy, except Morris. Meanwhile Luka and Sam are having communication problems, Carter gets a promotion Susan really wanted and Ray finds out a 14-year old who always comes in for free drugs has been raped.

After Carter finds out Kem's mother is hospitalized in Paris he decides to go there to tell Kem how he feels about her. Meanwhile, Ray makes a fatal error.

Casualties of a disaster flood the ER, which is short-handed because everyone is at Dr. Carter's going-away party because he's leaving the ER after 11 years. Dr. Pratt looks for the courage to confront his father, Charlie.

Sam and Luka go on the search for her runaway son, Alex. Meanwhile, Pratt and Lewis guide Abby, Neela and Ray, who have become R2's, on how to teach the new interns.

Much to Ray's dislike, a surrogate mother in labor doesn't want to have a C-section and endangers the life of the baby. Meanwhile, Sam tells Luka she and Alex are moving out. Pratt meets his half-brother and -sister, and Abby makes a difficult decision about a young boy.

Luka has a very bad day: New nurse manager Eve Peyton notices he doesn't want to work with Sam and tells him so. At the end of the day he's drunk and Abby takes him home.

The rainy night brings in diverse patients including a mother involved in a car accident with her baby, a man with a satisfaction facilitator, and a comatose patient who suddenly wakes up. Also, Sam steps up to Eve and her strict ways and Jerry gets struck by lightening!

A new attending, Dr. Victor Clemente, comes aboard and quickly makes a stir on the ER. Abby's breast cancer patient convinces her to take a long awaited test. Luka befriends a young woman who awakes from a six-year coma. Also, Weaver shows Clemente who runs the ER.

Pratt's half-brother tries to get him to make ends meet with his estranged father. Clemente treats an infant chimpanzee and involves Abby and Neela on the secret case. Eve promotes Sam and her first tasks is to fire a beloved nurse.

A kidnaped girl is the victim of police shooting. Abby is stuck in the middle of a disagreement between Luka and Clemente. Neela receives a phone call from Iraq. Later, Luka and Abby share a kiss.

The ER prepares to take in victims from a plane collision, while Neela and Pratt head out to the crash site where Neela makes heroic efforts. At the end of the day, Neela gets a surprising visit.

Gallant impulsively asks Neela to marry her that exact day, she says I do but soon gets cold feet. Morris stands up to Weaver on a patients course of treatment. Luka, Sam and Clemente treat a boy who contracted HIV from his mother. Also, Abby and Luka redefine their relationship and Luka is named the new Chief of Emergency Medicine.

Pratt and Weaver try to create a Christmas miracle when they work to save a girl wounded from gunfire. Eve gets into trouble after punching a disruptive patient. Also, Abby has a special gift for Luka.

Neela treats a religious teenage girl who turns out to be pregnant. Abby and Kovac struggle to figure out what to do with her unexpected pregnancy.

Ray helps an old friend escape from her abusive father. Dubenko volunteers in the ER but can't seem to handle a slow day. Abby and Kovac go baby shopping, while Neela gets unexpected and upsetting news from Gallant.

Dr. Nate Lennox, a former professor with ALS, is brought in as the progression of his disease is chronicled through his own flashbacks as he is treated by each of the doctors at one point. As Lennox wants to give up, Abby fights to convince him to keep on fighting.

An unexpected visitor puts Clemente in the middle of a domestic dispute. Meanwhile, Luka and Abby await test results on their unborn child; Neela struggles with her surgical elective and Pratt ends up with an unexpected suitor when he participates in a charity bachelor auction.

In the Sudan, Carter and a colleague struggle to save a woman who was raped by a band of militants. Back in the ER, Clemente asks to return to work after the shooting incident, but Kovac refuses. Meanwhile, Neela and Pratt have a work dispute, and, in a related incident, K.J.'s father shows up again in the ER.

When is it time to go out on a limb? Armand Assante guest stars as a patient who makes Sam an offer she might not be able to refuse. Luka must calm Abby’s baby-related fears after an incident at the hospital places everyone at risk. Kerry makes a difficult choice, and Neela joins a support group.

Abby and Luka desperately try to keep a young woman brought into the ER with stab wounds to the neck alive. As her condition begins to worsen, Clemente steps in and tries a risky procedure on the girl in order to save her life. Meanwhile, Neela pulls an all-nighter in preparation for a speech at a surgeon's convention, Ray treats a man claiming to have swallowed a bottle of pills, and Sam decides to take a part-time job with Richard to help her with childcare expenses.

When Luka answers a call for help, he discovers not everyone is pleased. Will he honor his commitment, or ask a colleague to step in for him? Abby and Morris wrestle with the strange case of a car crash victim. Having made a change in her life, Sam finds herself enjoying a few new perks. Neela has unexpected visitors, with even more unexpected news.

Pratt departs for Africa with attitude to spare but makes his first contact with harsh reality before the plane lands. Abby senses something is not what is seems when she treats a 12-year-old and her grandmother, then differs with Luka over the best course of action. A prisoner is brought to the ER with what everyone thinks is a fake case of appendicitis. Morris is dressed, and ready, to impress, but Albright’s not. It’s time for Kerry to return to work and Clemente doesn’t know when it’s time to leave.

Pratt gets to work in Darfur alongside Carter and his co-workers, but is troubled by astounding number of people needing care and finds himself making a dangerous journey.

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.

Chaos reigns in the ER when two prisoners are brought in for treatment, but instead plot a violent escape. Their desperate actions place one doctor in harm's way, and forces one nurse to become a tool in their plan.

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.

As Abby and Luka cope with their newborn's life and death struggle, the couple is shocked to receive a surprise visitor: Abby's mother Maggie. Meanwhile, Sam fears the prospect of criminal charges; Neela discovers that Tony Gates will be joining the ER team as an intern and Morris gets his job back while Weaver gets demoted.

Gates is assigned to the case of a closeted gay man whose partner clashes with his family; Neela meets her new surgical chief, Dr. Crenshaw; and Pratt must cope with the flood of new interns.

Abby and Kovac discover both the joys and difficulties of raising a newborn; Morris is wrongfully accused of being a child molester; Pratt has his trial-by-fire when he has to handle the ER alone, juggling multiple traumas, teaching duties and a troublesome intern. Neela continues to be the target of her difficult supervisor, and Sam discovers her sons latest extra-curricular activity.

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.

A belligerent young man with the flu turns out to be more than he seems, and presents a challenge to Morris and Sam when he refuses treatment. Abby's chance encounter with Curtis Ames leaves Kovac uneasy. Meanwhile, Pratt discovers a local church's risky drug exchange program, Neela and Gates square off, and Weaver gets an interesting offer.

A mysterious illness leaves little hope when a group of homeless kids enter the ER and one of them believes that Neela is a guardian angel in blue; Abby and Kovac clash over a possible case of domestic abuse; Pratt makes a shocking discovery about his brother, and Weaver is unexpectedly called into action when her television appearance becomes a real emergency.

Thanksgiving at County is quiet, with the normal number of routine (or nearly so) emergencies. But Abby makes up for the lack of excitement while returning to the hospital as the doctor on a helicopter transport.

Kovac and Gates treat a girl who appears to have been assaulted. When the police are no help with Ames, Kovac decides to confront the problem himself; Morris and other doctors work on a patient with an ice pick in his ear. Meanwhile, Ray tries to keep his new relationship a secret and Pratt can't fully deal when his half-brother officially comes out. Also, a new male nurse arrives.

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 having 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.

Kovac reacts negatively when he sees Abby giving extra attention to a patient; Ray and Gates clash over a patient, pinning Neela in the middle; and Ben takes things to the next level with Sam. Meanwhile, Pratt is under investigation and Weaver says a final goodbye to the ER.

Kovac finds himself in a tense confrontation with Curtis Ames, and Abby must act to protect her family. Meanwhile, Neela and Gates rush to get Meg to the hospital while Sam's new home is soon under threat from fire.

Abby and Sam try to treat an obnoxious, 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 cheerleaders accidental fall; Abby gets a prediction for her future; and Alex's troubles continue to intrude on Sam's work life.

A blizzard strands a family in the snow and Abby and Pratt quickly try to save the family. A gang shooting challenges Morris and Pratt. Meanwhile, Kovac and Abby begin making wedding plans, but their engagement might not be very secret; Gates struggles with the reappearance of his father and the possibility of losing Sarah; and Neela becomes jealous when Dubenko brings in a new surgical intern.

It's Sam's birthday, but she finds it hard to be away from her son Alex. Meanwhile, Sam meets a photographer taking pictures of a terminal patient and she gives Sam a new perspective on life. Dubenko's new surgical intern unsettles Neela during a trauma; Gates is shadowed by a new and nerdy intern and later must tell Sarah the truth that he may be her biological father. Also, Morris and Hope annoy Kovac and Abby when they try to help with their wedding preparations.

Kovac and Gates deal with a hopeless father whose son succumbs to heart failure; Pratt tries to resolve the tension between him and his brother; an Armenian man tries to be a good samaritan but ends up crashing near the ER; Abby sneaks in baby Joe when she worries his sickness may be worse than it seems; Also, Sam injures the instructor of a self-defense seminar.

In 12 hours, the ER will shut down. As Kovac is under pressure to take care of the patients before the final hours, he makes a pivotal decision about his future. Meanwhile, Sam befriends a photojournalist who returns only this time she's terminally ill; Pratt is concerned when his brother ends up in the ER drunk; Morris confronts Gates when he ignores his orders and angrily sends him home while Gates tries to defend his actions.

What is suppose to be a departmental dinner organized by Kovac turns out to be the surprise of a lifetime for Abby when she soon learns it's a surprise wedding, secretly planned by the eager groom. Meanwhile, at the wedding, ER staffers enjoy themselves with music and booze while Neela finds herself the center of unexpected attention between Gates and Ray, which leads to a drunken fight and a shocking conclusion.

Dr. Kevin Moretti, an ICU specialist bent on change, joins the ER team. Change comes elsewhere as Luka and Abby adjust to being husband and wife, Pratt tries to be a new man to his lady friend, Morris and Hope take things to the next level, and Ray goes missing. Later on, Luka gets a troubling phone call.

Season Finale: Luka postpones his honeymoon, leaving Abby, Joe and the ER behind to begin a different journey. Meanwhile, it's Moretti's first day as Chief of Emergency Medicine, and everyone feels the effects of his style, especially Pratt and Morris. Neela learns of Ray's fate, then joins an anti-war rally and finds herself in a dangerous situation. Gates faces a crisis on the home front.

Season Premiere. Moretti's first day is challenging as the ER is inundated with casualties from the peace rally - including Neela. Dubenko faces a crisis in surgery. Abby, Pratt and Morris conspire about how to deal with a shared problem. A new intern arrives unexpectedly, and Gates is reassigned.

Moretti begins to make his presence felt, as he implements changes in the way patients are seen. The ER staff differ on how procedure when a patient comes in with a bullet in him needed as evidence. Neela finds herself the object of more attention that she wants, or needs. Abby had passport woes, and struggles with the changes being made. Pratt and Morris find themselves forced to defend their actions, Hope prepares for a new mission, and Gates finds himself labeled the reject in his new assignment.

Two wounded police auxiliary officers present challenges in the ER. Neela settles in with Abby as she recovers, while Pratt and Bettina consider their relationship. Gates tries to get a patient on a drug trial, with Dubenko's help. And Morris is in a funk that not even a pretty woman can help.

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 reassigns Gates back to the ER and treats a couple involved in a car accident. Morris prepares to take his written board exams. Neela is assigned a young genius intern. Kovac plans to extend his stay in Croatia while Abby struggles with single parenthood.

Morris and Pratt cram for their medical boards when Morretti brings in a new attending physician to help with the load. Sam and Abby work on an attention-hungry patient who comes into the ER with elusive symptoms.

A power outage strikes on an unusually hot day, bringing nursing home patients suffering from hyperthermia to the ER. Abby and Pratt disagree about diagnostic tests for a fussy baby. Morris and Pratt get their board results, and the ER staff celebrates at Ike's. Moretti and Abby's interactions intensify, and Abby finds herself at a dark and frightening crossroads.

Everyone at the ER is happily surprised to see Luka back from Croatia. Great news awaits Neela. Sarah once again needs rescuing by Tony, and patients are causing problems for Morris.

It's time for changes at the ER when Anspaugh makes an unpopular decision. Abby has old demons to fight with, which distance her from friends and family. Even Luka seems to be at a loss to help Abby. Love is in the air when a secret romance blooms between two doctors.

ER's 300th episode finds Luka and Abby hurriedly preparing to travel to Croatia after Luka's father passes away. Luka confronts Abby about the estrangement between them, and she eventually reaches out and asks for his help. A man rushes to the ER when his wife is seriously injured in a car accident, and finds someone very unexpected there with her. Julia holds a service to bless the ER and remember the patients that have been lost through the years.

After being passed over for Chief of the ER, Pratt is looking for a hospital that will appreciate his talents. A former employee of the ER brings her sick son in for tests. Neela's cousin is in town for a visit, and Morris and Harold compete for her affections.

Abby is back from rehab and finds herself the object of scrutiny. She confesses to Pratt that Luka might stay in Croatia longer than planned. Harold seems to have won over Neela's cousin. Multiple victims from a fire fill the ER.

Neela's short visit in Ortho turns into a game of hockey. Bettina wants to take her relationship with Pratt to the next level, but Pratt is not keen on the idea. Gates and Sam disagree over a patient. Julia provides some spiritual guidance in order to ease a prison doctor's bad conscience.

Pratt and a new doctor on the scene disagree on how to teach the interns. Gates treats a young woman with serious heart problems. Abby heads to Croatia, and ponders whether and how to tell Luka about her unfortunate choices. Sam discovers that Julia has moved on in more ways than one.

Neela, worn out after being on shift for over 24 hours, has to make a quick decision regarding an accident victim's torn aorta. Sarah's grandparents are in town, and Hank is rushed to the ER after collapsing during an outing. Gates tries to convey to Sam that his feelings for her are serious.

Kovac is in Chicago looking for hospice-care work. Neela's aorta surgery has caused an infection in her patient. Abby treats a teen who has been beaten up. Brenner continues to cause problems for the ER staff.

There's been a jewelry robbery in town, and Neela finds out that one of her patients might have had something to do with it. Pratt makes an effort to save his relationship with Bettina, and Abby worries about her marriage, sensing that Luka may have given up on it.

Neela's aortic rupture patient is in need of yet another follow up surgery, and they are starting to take a toll on her. Morris talks with a shrink about his experience with the jewelery thieves. Abby needs to make a tough decision when a new opportunity is presented to her.

When a drunk patient is admitted to the ER, his actions endanger everyone at County. Pratt is still pursuing his dreams of becoming Chief of the ER, and Gates is worried about his future with Sam. Luka unexpectedly runs into Dr. Moretti.