Camille serves Aaron with divorce papers; Phillip benches Arthur from further surgery when Arthur's resting tremor begins to endanger patients; Aaron removes a brain tumor from an elderly patient; Jeffrey and Aaron separate conjoined twins.

Jeffrey runs afoul of the trustees when a grieving husband has second thoughts after allowing him to test an artificial heart on the body of the man's newly deceased wife; Alan comes to the rescue when a patient's HMO refuses to cover Aaron's operating on her very complicated and potentially fatal brain tumor; Jeffrey visits his wife Laurie, a straitjacketed patient in a mental hospital who apologizes for drowning their son Joey; Arthur's refusal to remove his wagging finger from Jeffrey's face during an argument leaves him with a bitten digit, and enables Jeffrey to diagnose the curable medical condition that's causing Arthur's resting tremor.

Arthur nearly fires Danny for failing to adhere to triage protocol, thereby delaying the treatment of a critically injured prostitute with AIDS; Phillip becomes the acting chief of staff after Hackett suffers a fatal heart attack during a little afternoon delight with Angela in the MRI room; Jeffrey and Arthur argue over the future of a baboon with the potential to prolong the life of Jeffrey's patient with heart failure and Arthur's patient with AIDS.

Jeffrey tells Nadine about Laurie's schizophrenia and the death of his son; Aaron and Camille grieve about their impending divorce; several members of a family of trapeze artists are brought into the hospital in critical condition after a devastating accident during a circus performance; one of Aaron's former patients reveals his bigotry when he refuses to allow Nadine to remove his diseased gall bladder and insists that Aaron or another Jewish surgeon perform the procedure; Jeffrey exhibits signs of a meltdown when, in the space of a few hours, outrageous conduct in a nightclub gets him mistakenly arrested for soliciting a prostitute and he vandalizes the car of a man who stole his parking space; Phillip incorrectly attributes Aaron's angry outburst at one patient minutes after losing another young patient in surgery to tensions with Camille, and threatens to fire Camille if there's a recurrence.

Phillip's religious beliefs and Jeffrey's grief over the death of his son put them on opposite sides of whether to convince a young mother to remove her infant from life support so that her daughter's organs can be donated to save the life of another baby; Karen deflects a flirtation from Jeffrey, but romantic sparks fly between her and Aaron.

Aaron, the staff, and the patients are caught in the crossfire when Antoine Metcalf, a gangbanger and career criminal, follows his latest victim into the E.R. to finish off the job he started, and sprays a room with automatic gunfire before hospital security shoots him down; Karen joins the staff, and successfully teams with Paula to remove hematomas that are preventing Marcus Lavelle from walking, but the trauma of witnessing his mother's being injured in the E.R. shooting leaves the little boy afflicted with hysterical paralysis and still unable to move although the surgery has left him physically fine; reluctantly operating on the shooter, Aaron jokes about how easy and perhaps appropriate it might be to cause Metcalf's death through a surgical hiccup, a remark which comes back to haunt him later when Metcalf dies soon after surgery and his family sues Aaron and the hospital for failure to provide adequate care; Arthur engages in a little ex parte communication to put in a good word

After Karen begins having seizures, Aaron discovers that she is terminally ill from the multiple brain metastases of a melanoma; Jeffrey resents having to perform surgery on a mobster about to enter the witness protection program; when the residents attempt to pull a practical joke on Jeffrey, they unwittingly provide comfort to a dying Karen.

Jeffrey strongly objects when his old nemesis is hired into the plastic surgery department, but they are able to set aside their differences to bring some peace to the mother of a young girl who dies during surgery; a nurse impedes Aaron's plan to allow Karen to die peacefully.

Camille has an innocent and unavoidable mishap in the operating room during a heart transplant on the rabbi who performed her wedding ceremony to Aaron, and blames herself when the rabbi dies later, even though her mishap had nothing to do with his death; an inexperienced new nurse stands up to Arthur; wracked with guilt, Camille reveals the operating room mishap to the rabbi's widow, and only Alan's ingenuity in demanding an autopsy keeps the hospital from a major lawsuit; Aaron and Camille have it out over his lack of emotional support after the rabbi's death, and each of them admit to the hurt caused by their divorce.

Tensions run high as hard truths ring out when Jeffrey, Danny, Camille, Maggie, Aaron, Arthur and Phillip are quarantined in an empty operating room after a possible exposure to Ebola; Jeffrey and Danny perform an emergency bypass after Arthur has a massive heart attack; Aaron and Camille reconcile.

The staff has its hands full when a man suffering from the after-effects of taking amyl nitrite suffers one complication after another, thereby necessitating multiple surgeries, and Alan takes one for the team right on the nose when he strains credulity in attempting to put the patient's situation in the best possible light; Geri and Jeffrey make peace; Camille contemplates having some plastic surgery after Aaron suffers from performance anxiety on their first post-reconciliation date; Jeffrey agrees to help Laurie put on the Institute's Christmas concert, but the preparations for the event begin to overwhelm her and put additional strain on her already fragile state; Danny and Maggie can't keep their hands off each other; Jeffrey confesses his despair about Laurie's condition and its effect on his life to Camille.

Phillip is unable to save a promising young boxer who succumbs to the fatal effects of steroids his father gave him to enhance his performance in the ring; a pregnant young teenager carrying a baby with a heart defect seeks Alan's help when she is unable to find adoptive parents for her infant; Aaron fires Angela after his tax audit reveals that she's been embezzling money from his pension plan.

Billy Kronk, a hotshot young surgeon and recreational hockey player, arrives in the E.R. with a critically ill teammate and immediately takes charge, steamrollering over Phillip; Alan deflects a suit by Nabbott, but not before bristling at Harold's ""toad"" routine in court and being thrown into jail for contempt; Billy convinces a psychotic mugger with a history of pica who has bitten off the finger of a concert flautist during a robbery to submit to an endoscopy to retrieve the digit; as Geri successfully completes the reattachment, Billy and Phillip discover a second finger in the thief's digestive tract, and realize that the musician has been given a digit belonging to yet another of the mugger's victims.

Laurie asks Jeffrey for a divorce so that she can marry Gilbert Weeks, a lawyer who is also a patient at the Institute; spurred by this news, Jeffrey suggests that Aaron perform an experimental procedure which may cure Laurie's schizophrenia; fearful that Laurie will no longer love him if she is cured, Gilbert goes to court to stop the procedure, citing Jeffrey's conflict of interest and contesting his guardianship of Laurie; although she is torn between the two men that she loves, Laurie decides that her future is with Gilbert and declines the surgery; Billy becomes a member of the staff, and agrees to do a consultation on Tamara, a teenaged patient of an old friend, Dr. Dennis Hancock; after Tamara is diagnosed with breast cancer and refuses to have a mastectomy and reconstructive surgery despite warnings from Billy and Geri that she will die without the surgery, Dennis uses just the right approach to change her mind and allay her fears of disfigurement.

When the gun belonging to a critically wounded police officer drops out of his holster in the E.R., the distraught brother of a man waiting for a donor heart picks up the weapon and threatens the staff unless his brother receives an immediate transplant; as Aaron and Danny operate on the wounded officer, one of the exploding bullets with which he was shot goes off and severs two of Danny's fingers; Geri performs a successful reattachment, but Danny may be facing the end of his career as a surgeon.

The staff works to save a young boy who was submerged in a frozen lake for several hours; Jeffrey and Geri have a little digestive mishap on their way to pursuing a relationship; Dennis fights to get an experimental treatment for a patient with AIDS, and finds an unexpected ally in Alan.

An explosion sends a dry cleaner to the ER. Dr. Kadalski is pressured to change his unorthodox methods when he treats a man who compulsively pulls out his hair. A fearful Birch lets off steam at Jeffrey as baby Alicia's condition worsens.

Dr. Kronk's feelings towards his girlfriend undergo changes when he find out about her past. Geiger's heart patient develops an aneurysm which would take him off the heart recipient list unless highly experimental methods are tried. Meanwhile, Dr. Hancock's ejection from his clinic leads to bringing the HMO provider into the courtroom.

Dr. Kronk makes a rushed decision to rescue a man by amputating his leg with a chainsaw, only to discover later that the man is a place kicker. A friend of Aaron's with Parkinson's disease comes to him for an operation...bringing his own donor material. A ex-nurse is admitted into the hospital and is given special treatment by Dr. Nyland, whom she used to date.

When the Board of Health closes the hospital doors after several patients die from a deadly staph infection, the staff scrambles to find the source of the infection; Jeffrey and Geri help each other work through feelings of grief, loss, and guilt.

A troubled Dr. Geiger seeks a blessing from his institutionalized ex-wife so he can continue his relationship with Dr. Infante. A dying AIDS patient hopes Hancock can arrange a surgical procedure that would allow him to see one more sunrise.

Following Dr. Joseph's witnessing of Dr. Geiger's actions, the medical board suspends him until his case can be reviewed. However, there is some disagreement among the hospital's staff as to whether or not the suspension is in their best interests.

Dr. Nyland pulls a switch with Dr. Kronk in order to avoid a charity function, but they have to face the consequences over somecmisunderstandings. Misunderstanding fills Aaron's life when his father barges into the hospital with a patient who is also his fiancee. Geiger finally understands that he may be causing more ripples than he thought.

Diane helps her friend Allison harvest sperm from Allison's comatose husband before his life support is turned off; Aaron realizes that the reconciliation with Camille isn't working, and they agree to go through with their divorce; Billy takes Danny to task over his medical mistreatment of a mentally unstable woman; Jeffrey and Kate manage to put aside their differences over her cost cutting proposal for the hospital long enough to save the life of a young pre-med student; Alicia is christened.

Dennis struggles over whether he should listen to his gut, or to Jeffrey's advice, in treating a man who doesn't speak English; Aaron is upset when Alan gives Camille advice about their property settlement; after Billy recommends amputation to a man with a gangrenous leg, Diane offers the use of maggots as an alternative treatment, but the patient has a great deal of difficulty in overcoming the ""ick"" factor of Diane's suggestion; Phillip seriously injures his opponent in a charity boxing match; Aaron and Camille sign the papers that finalize their divorce.

Billy arrives home just in time to save his dog Gordie from the fire that's engulfed his apartment, and ends up rooming with a reluctant Danny until he can find a new place to live; when a teething Alicia keeps her father up at nights, an exhausted Alan is thrilled when Diane offers to help out; when a racist teenager on the transplant list refuses the heart of a murdered black teenager, the hospital offers it to another candidate, but the boy's mother sues to have the heart transplanted into her son; Alan decides to get back into the social swing by asking Diane out on a date; Kate's inattention to pre-op labs results in the post-op death of the transplant patient; Danny overcomes his dislike of Gordie long enough to notice that he's critically ill, and by acting quickly, saves the dog's life.

Geiger second-guess Austin's choice of a non-surgical treatment for a heart patient. Grad gets a surprise visit from an old beau. Hancock asks for Camille's help in coordinating a new home health care program.

A violent storm on Halloween night knocks out the hospital's power immediately following the arrival of several auto-accident victims. Nyland and Atkisson briefly renew their romance. A new doctor shows up for duty, and is immediately put to work delivering a baby.

Watters blames Birch for their poor showing after they're ambushed by a state senator during televised health-care hearings. Sutton operates on a pregnant woman's unborn child. Laurie remarries and asks Geiger to attend the ceremony, which will be presided over by ""Evita Peron.""

Geiger's bravado is put to the test when hospital counsel Alan Birch is shot by street thugs. Meanwhile, Grad agonizes over not being able to help Alan and Watters regrets his recent harsh words with the lawyer.

Shutt finds himself revitalized by a frustrated MS patient who refuses to quietly accept that Aaron can't help him. Dr. Sutton comes up with a way to exorcise Geiger's spirit from the hospital. Watters finds solace with a special visitor.

Kate is stricken when she realizes that her negligence due to exhaustion caused the death of a young woman during surgery, and considers assuaging her guilt by informing the woman's parents of her error; Billy and Danny decide to help a teenager running a unlicensed clinic for indigent patients; Judge Aldrich retires from the bench and comes to work at the hospital as Alan's replacement; Camille's drug seeking behaviors continue; Diane has second thoughts about her research project when she realizes that she's become attached to the orangutan that she's successfully infected with AIDS.

Aaron is baffled when a seizure lands Camille in the ER. Nyland's holiday vacation plans are suddenly sidetracked by a delivery of supplies to Ricky's makeshift clinic with a Santa'-clad Hancock. A promising teen athlete fears that an operation could cost him the chance to play major league baseball. Grad meets a sweet but shy veterinarian.

Watters steps in and asks Geiger to take on Austin's transplant patient as she struggles with her ex husband for custody of their daughter. Sutton brings a brain-dead woman into the hospital to deliver her baby.

Judge Aldrich's tenure as Alan's replacement is cut short by illness; Amy, an old friend of Danny's from medical school, joins the nursing staff and clashes with Camille over the care of a terminally ill patient; Kate and Billy hook up, but decide that they won't repeat the experience after they clash professionally during experimental laser surgery on an elderly cardiac patient; Amy rebuffs Danny's advances.

Hancock's practice and his freedom are threatened when he saves the life of a hemorrhaging pregnant woman by aborting her fetus, which stirs up strong emotions when the woman denounces his actions. Kronk recoils at first from treating a drag queen with AIDS. Another new lawyer faces a baptism of fire as hospital legal counsel.

A heart-transplant patient returns to the hospital with chest pains and emotional and personality changes that challenge the notion of what really is exchanged in a transplant. Shutt is approached by a direct, self-confident psychiatrist who insists he perform psychosurgery on a 12-year-old boy with an obsessive-compulsive disorder that severely limits the life he can lead.

A friend of Kronk's seeks his advice about a health problem she thinks resulted from her sex-change operation. Austin treats an impressionable teenage boy with a heart condition and a crush on her. Dr. Konstadt, off her medication, acts injudiciously when Shutt seeks permission from a reluctant board to perform surgery on Eric.

Aaron proceeds with Eric Dipretto's psychosurgery while Austin campaigns for the position of chief of surgery and Bix continues to lose control. Kronk is determined to perform a controversial intestinal bypass on Nyland's former boss and good friend, a restauranteur who just wants to enjoy a good meal again.

Grad and Kronk reluctantly team up to counsel an inexperienced couple on sexual techniques. Dr. Sutton finds himself unnerved by a sexually precocious young woman at Dr. Hancock's clinic. Aaron tries befriending a resident, but finds himself misinterpretted.

Dr. Watters befriends a 12-year-old girl when she's admitted with an apparently self-inflected wound to her transplanted kidney. Austin has another rough day, with the shakes during a surgery and a message from her ex-husband that he might be moving to Boston and taking their daughter with him. Diane finds out about Billy's previous relationship with Kate.

Kate loses her control and her compassion when her father is admitted with an operable surgical condition but refuses it on religious grounds. Geiger turns up again at the hospital, this time as part of a clown troop there to entertain the patients. Sutton delivers a baby with ambigous genitalia whose parents are equally ambigious about they feel about their offspring.

The ER looks like the only game in town as avery disturbed family one by one injures each other during a therapy session. Geiger and his fellow clowns return to cheer up children injured in a bus accident, with a musical pantomine of ""The Emperor's New Clothes.""

Sutton's mind rells as wives two and three ask him for a very great personal and professional favor and wife one chacks in for a serious medical problem. Kate anxiously awaits news of who will be appointed as the new head of surgery. Dr. Shutt performs delicate surgery on a wealthy quadriplegic who cannot be anesthetized, and whose beautiful fiance attracts Nyland's attention.

Tommy places a bid to buy out the hospital with the intention of firing Kate as soon as the deal goes through; as Valerie continues her affair with Danny, Jack lets Danny know that he's aware of their relationship; Elizabeth is readmitted after Andy beats her again, and Andy takes his revenge when Dennis attempts to help his sister escape the cycle of spousal abuse; a mysterious biohazard accompanies a patient admitted to the E.R., and immediately begins to fell the staff; after Kate pleads the hospital's case, Jack agrees to counter Tommy's offer, but only if Phillip fires Danny; Kate and Tommy threaten to expose each other's secrets; after Diane's work for the last two years is called into question and her grant money is suspended, she decides to go to Africa to do research with a colleague; Tommy courts Aaron's support; feeling under-appreciated and ill-respected, Camille resigns; realizing that Tommy will stop at nothing to destroy her, a desperate Kate flees with their daughter an

A poisonous gas is released in a bank and the doctors try to contain the gas, that is threatening many lives including Dr. Hancock.

A cardiologist in NASA's Doctors in space program has a heart attack and Kate takes the doctors place in the program. Dr. Shutt has a patient who needs to tell his father, an Orthodox Rabbi, that he is gay.

Hancock accuses Watters and Austin of racism when they refuse to operate on a black patient. One of Shutt's patients commits suicide when the medicine needed isn't covered by insurance.

Grad accuses a mother are starving her infant to death. Shutt and Catera disagree over a neurological patient. Austin announces her plans with NASA, and Watters taked away her status as Chief of Surgery. Yeats uses his ""sixth sense"" to diagnose a patient.

The hospital prepares for the Doctor of the Year party, and several old friends drop by. Watters goes into a virus-induced coma and gets some words of wisdom from Alan Birch. Camille Shutt returns for the party and Aaron discovers he still has feeling for her. Dr. Nyland returns to the hospital and reveals that he has really changed his life. Geiger also visits the hospital.

Kate discovers that a patient is using Viagra to cheat on his wife; Jack gives a blood transfusion even though it's against the patient's Jehovah's Witness religion; a musician fears his creativity may be stifled by the medicine Aaron prescribes for his bipolar disorder; Joe's son drives the staff crazy as he roams the hospital behaving exactly like his father.

Gordan teaches Kate how to fly. Hancock accuses a police officer of shooting a homeless African-American.

A celebrity dies and news crews invade the hospital to cover the story.

Billy's mother shows up at the hospital and announces she is about to give birth. The star of the road company version on ""Jesus Christ Superstar"" comes to the hospital when the star is ill. Yeats former teacher comes to the hospital with chest pains.

Wilkes must face the parents of a child brought into the ER when it becomes clear that Raymond was responsible for the child's injury. NASA starts interview Kate's colleagues. One of Aaron's patients is attracted to him.

A member of Jack's basketball team sustains a near-fatal injury during a game; Bobby disagrees about the need for his patient to have heart surgery.

Aaron struggles with the loss of a patient; Billy is attracted to Emily's babysitter; a couple asks Bobby and Dennis for help in creating a baby with a genius I.Q.; Joe tries to decide who should go into the hospital's fallout shelter in an emergency.

Kate discovers that she has developed an ovarian cyst which could destroy her plans with NASA. After Kate hears this news she agrees to go to a retreat... that Yeats is leading.

During surgery to resolve an HIV-positive woman's post-partum complications, Diane accidentally cuts herself and is exposed to the virus; problems arise between Jack and Lisa when he discovers that she's been seeing Robert; a homeless man takes shelter in the hospital's main entrance; an unidentified man is hit by a train after trying to save a child; Jack takes up golf in the hospital.

McNeil performs a hand transplant on the patient, and uses the patient's dead mother's hand. Kate is accepted by NASA. An old childhood friends visits Watters and asks for one of his kidneys.

Jack returns after his brother's death; fearing the impact of HMOs on his practice, Joe begins to sell doorway products; Billy's friend comes to the hospital for a heart transplant, and ends up getting an experimental procedure after the hospital receives the wrong organ.

Billy ponders euthanasia when Gordy is diagnosed with rheumatoid arthritis; Lisa tries to help a woman with metastatic breast cancer get into an experimental group even though the woman doesn't fit the study parameters; Aaron's patient confesses to murder.

Kate confronts a world renowned surgeon who's harassed her in the past; Diane's patient has a flesh-eating bacterial infection.

Diane tries to help grieving parents when their three year old child dies; Aaron is institutionalized after an experiment backfires.

A mother gives birth to twins, one black and one white. Kate is threatened with a lawsuit after making a rude comment.

Dr. Hancock's patient, who was using fertility drugs, gives birth to 8 babies.

Kate meets up with an old boyfriend, who turns out to be an ex-husband. Lisa tried to prolong the like of a pregnant woman with brain cancer. Cacaci forces Aaron to investigate his charge that Phillip had an affair with a patient.

The E.R. is flooded with teenagers poisoned by an unknown rave drug; Kate and Sara are hit by a drunk driver; Phillip's fate is decided.

Aaron consults Dr. Gina Simon, a pediatric neurosurgeon after being presented with a 9-week old baby suffering from seizures. Jeffrey Geiger returns to the hospital and promptly fires half the staff, whom then sue to get their jobs back.