Third-year med student Lucy Knight reports to the ER for the first day of her rotation. Greene takes a paternal interest in her, helping her get acquainted, but she gets off to a bad start with the irritable Carter. The rest of the day finds her informing a wife of her husband's terminal condition, comforting a pregnant woman, getting locked on the roof and trying to figure out Weaver's "Tour on Tape."
Dr. Corday's father visits from overseas in an attempt to convince her to join his medical practice. Lucy continues learning, earning more respect from Carter, who is having trouble being an RA in the dorms. Meanwhile, Peter takes Reese in for another hearing test, Carol hires a nurse practitioner to help out in the clinic, and Weaver continues to remind Doug of the way he bypassed her authority.
Benton performs dangerous surgery on a bomb-carrying man who was shot at a factory. Dr. Ross receives some good news that Dr. Weaver doesn't embrace, but she has no recourse. Rachel encourages Dr. Greene to help a horse that is in pain. Jeanie Boulet returns from her vacation.
Lucy finally admits to Carter that she doesn't know how to start an IV. Weaver interviews for the job as the ER Chief. Benton keeps his son's disease a secret. Jeanie intervenes when she finds out a liver transplant candidate is drinking again, and later asks Doug if she can be assigned to work for his pedes project in the ER. Corday gets stuck as the intern of dismissive and insulting Dr. Dale Edson.
It's Halloween in the ER, and the medical students throw a party; as a result, Carter decides that Lucy isn't mature enough to take responsibilities. A candidate for the ER Chief position arrives from New York and drives home disappointment for Kerry. Mark screws up when he doesn't recognize a homeless schizophrenic woman is pregnant before treating her. Benton treats Corday to a fun Halloween.
The board decides to extend the search for a new ER Chief, leaving Kerry waiting for a decision. Benton visits a doctor who is deaf/mute and he realizes that there is nothing "wrong" with his son. Mark saves the life of a gay prostitute and then tries to get the kid to avoid reckless behavior. Carter loses his Resident Advisor job because of Lucy, then blames her for not going along with his plan to defraud an insurance company, but she inadvertently leads him to shave off a nasty-looking beard he'd been growing. Corday saves two lives and impresses Benton enough that...
Carter and Weaver become unlikely roommates. Lucy is having problems with Carter, and Greene picks up on their squabbling. Corday works long shifts which leads to her exhaustion and a critical medical error, causing a rift with Dr. Anspaugh and problems for Benton. Greene has unpleasant flashbacks when he's hazed by the well-meaning paramedics. Jeanie worries when she and Doug treat a young boy whose childlike mother clearly depends on his 6-year sister to make all decisions. Kerry rediscovers her joy of practicing medicine and decides not to pursue the open ER Chief ...
A man arrives at the ER with his daughter who is gravely injured, then leaves the ER leaving his daughter in a critical situation because her father is the only one who is a match for her blood type. Carter and Lucy alternately bicker and work well together as they try to track down the father, and put their problems behind them at the end of the day. Meanwhile, snafus involving the blood supply lead Benton to perform an unprecedented operation to save the little girl.
Corday faces M&M where the board were discussing about the mistake that Corday made after she gave the wrong diagnosis to a patient. She decides to take the offensive and let the board know how wrong it is for her and any other doctor to work 36 hours. The board decides to do nothing about it, and she later decides to amicably end her relationship with Benton. At the hospital arrives Ruth Johnson who was born 100 years ago in that same hospital and shares some experiences with Carter. Carol is horrified by the true story behind a young boy's fatal shooting.
It's Christmas day in the ER. An 18-year-old boy arrives brain-dead, and Carter has to convince his parents to donate his organs, since a 16-year-old girl needs a liver. Benton risks his career by preventing Romano from operating under the influence. Ross and Hathaway have a religious dispute over how to deal with a pregnant 13-year-old. Corday is charmed by a musician who is facing surgery for testicular cancer. Dr. Lee flirts with Mark but turns out to have some major issues and strange story-telling habits.
Dr. Greene discovers that Amanda Lee is a fake and Anspaugh never saw through her credentials. When Lee finds out that Greene is suspicious, she locks him with a patient inside. An old friend of Greene's recommends him for a NASA mission. Benton's son is having difficulties in day care. Doug and Carol help the exhausted mother named Joi of a little boy named Ricky who has a terminal illness. Carter is jealous when Lucy goes on a date with Dale.
Lucy begins her surgical rotation under Benton and Corday. Romano offers to get Corday's fellowship reinstated and asks her to assist him in surgery. Weaver interrogates Corday, asking if Romano ever sexually harassed her. Corday denies it and concludes that Doyle must have filed charges. Ross jeopardizes a liquid pain medicine study by surreptitiously giving some of the drug to Joi's son, Ricky. Greene discovers the secret and informs Weaver. They decide not to tell Anspaugh because, by violating protocol on a federally-funded trial, the hospital would be unable to ...
Ross helps the mother of a dying boy; Benton attends a parent/child signing class. Corday doesn't give her account in the case against Dr. Romano. Romano blackmails Corday into dropping her support for Doyle's harassment lawsuit against Romano, but Kerry gets Romano to rewrite his insulting and inaccurate review of Doyle's job performance. The ER unites to help an injured woman who needs to find temporary homes for her many dogs as she gets treatment. Mark treats the hospital janitor, Mobalage, whose injuries suggest he has been tortured in the past. Carter discovers ...
Doug faces possible criminal charges after Ricky Abbott dies when Ross shows Joi how to give Ricky a lethal dosage of medication. Doug is delegated to desk duty, Carol's clinic is shut down for acquiring the P.C.A. machine for Ricky, and Greene and Weaver face future disciplinary action for not reporting Doug's earlier mistakes. Meanwhile, Carter and Lucy discover a mutual attraction, Benton studies with a sign language instructor, and Romano begins his first day as acting ER chief.
Greene assists paramedics in treating injured children at a school bus accident. En route, Doug and Jeanie survive their own accident. Kerry stops Doug from treating Jeanie... or any other patient. But when Jeanie is treated, Kerry and Peter realize she has hepatitis. Doug decides to resign and leave Chicago for the Northwest and asks Carol to come with him. Meanwhile, Carol steps down from running the clinic so that Anspaugh will keep it open.
Carter deals with tenant drama at an apartment tower during a ride-along that later has deadly consequences, Lucy has to hide a cancer diagnosis from an ill woman at the behest of the patient's family, Carol finds out she is pregnant, Kerry reflects on her own family issues when an injured wrestler comes to the ER, and Greene continues to help Mobalage, who may be deported if he can't tell the INS about the abuse he suffered in Nigeria.
Greene uses a past trauma to help Mobalage save himself from deportation. Carter applies for chief resident and spends the day in charge of the ER, where he misunderstands a case involving the many broken bones of a baby, while Lucy begins her first psych rotation. Weaver may have found her biological mother, but defies a DNR order to find out for sure. Benton and Corday clash over a surgical fellowship.
Carter mentors a talented teen from a very rough neighborhood. Romano is upset about Benton's interest in the fellowship. Lucy continues impressive work in her Psych rotation, treating a law student with homicidal impulses and an angry youngster who is being severely over-medicated. Jeanie continues to grapple with her Hepatitis-C but gets a huge boost from a kindly minister. Hathaway reveals she is pregnant after a kid kicks her in the stomach, risking her baby. Greene and Corday attempt to go to a ball for trauma physicians but end up getting lost repeatedly while ...
Romano observes the ER, and rubs the staff the wrong way. Lucy finds out that an elderly patient's bedsore is really much more. Carter breaks up with his girlfriend. The power goes out at County General, and the doctors must keep critical patients alive. Corday investigates the rape of a comatose patient.
The ER has to deal with a stripper and some shady dealings from apparent FBI agents. Lucy reveals to Carter that she's still on Ritalin. Hathaway begins to reveal her pregnancy to those closest to her, including a fax to Doug. Dr. Anspaugh decides that the trauma fellowship will go to Benton, who then faces anger from Romano and Corday. A car accident involving teenagers may have been alcohol-related and leaves one teenager with grievous third-degree burns.
The rest of the staff finds out that Hathaway is pregnant. Benton begins a custody battle for his son when Carla Reese reveals an intention to marry Roger and take the child to Germany. Weaver rescues a toddler that has been drugged. Carter's protégé is mugged and beaten up. Greene and Corday fall in love.