Lucy Knight, una estudiante de tercer año de medicina, comienza su primer día en la sala. Aunque impresiona a los doctores con su habilidad de responder preguntas médicas, sus intentos por ayudar a los pacientes son torpes. Puesto a prueba, Ross debe reportar cada procedimiento ante Weaver. Mientras tanto, un paramédico le pide a Greene que considere un puesto como director del distrito médico para el Servicio Médico de Emergencias, un trabajo voluntario.

Para ahorrar un poco de dinero de la renta, Carter vive en el dormitorio para estudiantes como asesor residente. Mientras visita a Corday en su departamento, Benton conoce a su padre. Corday sabe que la única manera en la que se puede quedar en County General es reiniciar su proceso como interno, lo que decide hacer eventualmente. La prueba de audiología que le hacen a Reese revela que está sufriendo una profunda pérdida de audición y necesitará utilizar audífonos.

Greene accede a ayudar al comité de investigación a evaluar a los candidatos que pueden llenar permanentemente la posición de internado como jefe de medicina de emergencia. A pesar de las objeciones de Weaver, Ross obtiene la plaza como nuevo médico pediatra de emergencias. Greene atiende a un caballo constipado y se convierte en el héroe de Rachel. La primera asignación de Greene como director de la sala de emergencias, lo coloca en una situación riesgosa, cuando atiende a un terrorista.

El miembro herido de una pandilla intenta abandonar la sala de emergencias para obtener venganza. Benton mantiene la discapacidad auditiva de Reese en secreto. Jeanie le dice a Ross que quiere ser su asistente en la sala de emergencias pediátrica. Weaver hace una entrevista para aplicar como jefe permanente de medicina de emergencia. Hathaway le confiesa a Ross que podría estar embarazada, pero después descubre que no es así. Lucy lleva un cadáver a un lugar equivocado al llevarlo a la morgue.

Jennifer planea reubicarse a St. Louis y llevarse a Rachel con ella. Carter pone a Lucy a cargo durante la fiesta de Halloween en el dormitorio para que él pueda hacer la investigación para su presentación. Pero los problemas surgen cuando dos estudiantes de medicina toman medicamentos con alcohol y casi mueren. Una operación revela que la pequeña niña de una pareja, es genéticamente un niño. Corday, ansiosa por celebrar Halloween, recibe una grata sorpresa por parte de Benton.

Un adolescente gay está severamente golpeado y dejado por muerto en la calle, y Greene arriesga su vida para alcanzar el chico en medio de los disparos; Carter encuentra un nuevo lugar para vivir; Corday sugiere convertirse en la pasante de Benton; dos hermanos se pegan juntos con cemento de alfombra.

Dr. Corday commits a deadly error after being on-call for nearly 36 hours straight. Peter visits Dr. Kotlowitz and receives encouragement regarding a cochlear implant for Reese. Dr. Amanda Lee, a prospective new ER chief, visits. In the wake of a failed pregnancy attempt, Carol lashes out at a mother using abortion as a means of selective birth control. Carter and Lucy feud when Carter accidentally uses her palm computer and finds out what she thinks of him. Mark panics during a paramedic initation.

Carter and Lucy scramble across Chicago to find a dying girl's father who's a perfect match for her very rare blood type. Benton operates without transfusions to save the little girl's life.

Carter plays tour guide for Ruth Johnson, who was born in the hospital 100 years ago to the day, and her large family. Carol treats a boy who was hit by a car and tells a story of being chased, his friend being shot in the process. Peter observes Kotlowitz install a cochlear implant and decides to wait before scheduling an operation for Reese. Mark dines with Dr. Lee, new ER chief. Dr. Corday proposes radical changes in scheduling at an M&M conference, and later decides to break off her relationship with Benton.

Benton's attempts to get away to Carla and Reese on Christmas Eve are continually thwarted by Romano, culminating in Benton forcing the drunken Romano away from a patient. Carter believes he's found a Christmas miracle when a teenage girl with a rare blood type needs an organ donation at the same time a brain-dead patient with the same blood type is in the hospital. After witnessing Dr. Lee rifling through Greene's locker, Jerry becomes convinced that she's stalking Mark.

Amanda Lee's obsession with Dr. Greene comes to a head when Mark inadvertantly digs up old med school records damaging to her career. Carter tries to save Lucy from Edson's advances. Peter treats Dr. Parks' grandchild, who interprets for her deaf mother and grandmother. Police officer Reggie Moore asks Jeanie out. Kerry receives a call from someone claiming to be her mother. Doug receives a job offer from Portland.

Doug jeopardizes future federal grants for the entire ER when he breaks a double blind study by giving a sample drug to an ailing patient. Doyle lodges a sexual harassment complaint against Romano, hoping Dr. Corday will lend support. Lucy begins her surgery rotation under Benton's tutelage. The two of them treat a man claiming to be 140-years-old. Mark declines to proceed in the NASA program. Carol questions Lynette's intentions when she hosts a women's health clinic for African American women only. Mark goes to bat for Pickman when she inadvertently leaves a severely injured man at an accident scene.

Ricky Abbott returns to the ER. Doug forges papers to allow Joi to treat Ricky at home. Corday decides to back out of the Romano sexual harassment investigation after he threatens to expose her relationship with Benton. Romano is later named Acting Chief of the ER. Dr. Greene treats a Nigerian janitor for back pain and impotency. Carol and the nurses watch a bunch of dogs when their owner is hospitalized. Carter diagnoses a med student with Hodgkin's disease. Kerry initiates a search for her biological parents.

Doug faces possible criminal charges after Ricky Abbott dies when Ross bypasses system lockouts to enable Joi to give Ricky a lethal dosage of dilaudin. 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 tampering with the double blind study. Carter and Lucy discover a mutual attraction. Benton studies with a sign language instructor.

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. Doug decides to resign and leave Chicago for the Northwest and asks Carol to come with him. She decides against it, but he leaves anyway. Carol steps down from running the clinic so that Anspaugh will keep it open. Jeanie discovers she may have contracted hepatitis. Hospital janitor Mobalage's wife is stabbed.

Peter accepts Romano's suggestion and takes a two-week job in Minnesota to earn some extra money. Unfortunately, before he gets a chance to leave, he's transferred to backwoods Mississippi, where the hospital is only a two-room building. Peter battles local racism, delivers a difficult infant while battling the grandfather's concerns that the child might be black, and uses unorthodox methods to save two shrimp boat workers. Meanwhile, back in Chicago, Jeanie's condition worsens.

During a paramedic ride-along, Carter is forced to drive the ambulance while fleeing a riot scene and inadvertently runs over a teenage boy. Later, a paramedic is shot by an angry mob looking for the driver of the ambulance. Carol is despondent following Doug's departure. She later discloses that she's pregnant. Kerry is intrigued by an injured pro wrestler and his relationship with his father. Lucy tangles with an Asian family that requests their matriarch not be told of a cancerous tumor. Jeanie turns down dates with both Dr. Baker and Reggie, telling each she's seeing someone else.

Romano forces Benton to choose between the trauma and cardiothoracic fellowships. Carol worries that she may have lost her child. Corday and Greene bond on the way to a medical conference. Carter mentors an aspiring teenager. Lucy, on a psychiatry rotation, treats an overmedicated foster child. Jeanie finds her faith while treating a reverend.

The hospital suffers through a series of power outages. Carol's decision to send Doug a fax about her pregnancy is thwarted by the power outages. The staff is on alert after a raped and beaten patient is found in a hallway. Romano begs Corday to stay in trauma. Carter and Roxanne break up. Carter and Lucy treat a pheromone saleswoman.

The ER docs tend to three teenagers who were in an accident on the way to their senior prom. Greene and Carter treat the most severely injured, a boy suffering from third degree burns over 80% of his body. Benton receives the ER trauma fellowship. Carol finally tells Doug about her pregnancy; Kerry also figures it out. Mark and Elizabeth draw closer. Lucy tells Carter about her Ritalin addiction. "FBI agents" bring in a shot stripper.

Carol's pregnancy becomes public knowledge as she learns that she's having twins. Lucy has problems trying to go off Ritalin. Peter learns Carla plans to move to Germany. Kerry finds an abandoned youngster and brings him to the ER. Mark and Elizabeth discuss their relationship. Jeanie and Reggie draw closer again.