ER

Abby wakes up after the ambulance explosion and checks on the others. A mother and daughter are rushed in and Abby misdiagnoses the case. Morris and Neela struggle to keep up.

Dr. Banfield's arrival and tough attitude causes the ER staff to feel defensive. Gates and the new interns fight to save the life of a terrorist while risking their own lives.

Neela is disappointed when she finds out Abby's good news secondhand. When a gunshot wound victim comes into the ER, the new chief, Catherine Banfield, and Abby butt heads on how to treat the patient. Abby comes to Sam's (series star LINDA CARDELLINI) defense when she goes before a nurses disciplinary board.

After Banfield defends herself from a street criminal, she and Dr. Gates treat a young gymnast with suspicious injuries indicating abuse. Dubenko's back on the surgery team.

It's Halloween in the ER and there are all sorts of tricks and treats in store. Morris surprises Neela with an unexpected guest - as former ER star SHANE WEST reappears.

COURTNEY B. VANCE guest stars in an episode when everybody seems to know best. Both Morris and Neela have authority issues with Dr. Banfield and Gates upsets Sam.

Trying to rescue a three-year-old girl from drowning in a nearby lake, Banfield is reminded of her own experience at County with Dr. Greene (ANTHONY EDWARDS) caring for her son.

Gates is obsessed with finding a homeless war hero - much to Sam's chagrin. And while Neela's intern involves the department in a lawsuit, Brenner loses his cool with a patient.

Morris and Banfield are snowed in and trapped at an ER conference in Nebraska. Back in Chicago, Alex and Sarah go behind Sam's back and get into a terrible car accident.

Morris receives an unwanted package from his father at the ER doorstep. Meanwhile, Sam is anxious about getting Alex off of the ventilator after his accident.

Banfield treats two brothers that come into the ER. Meanwhile, Gates is upset with Sam over the fact that she never told him that Alex was released from the hospital.

After a crazy day trying to save a young girl with sickle cell anemia, Neela goes in for an attending interview and is surprised to see Dr. Elizabeth Corday (ALEX KINGSTON).

Love is a complicated operation in the ER as Gates can't seem to shake his feelings for Sam and Neela gets flustered when Brenner returns from Australia.

Dr. David Morgenstern (WILLIAM H. MACY) takes a trip down memory lane as he stops by County General and Sam's sister (SHANNON WOODWARD) pays an unexpected visit.

After a devastating car accident in the ambulance bay leaves a mother severely injured, Brenner struggles to find a family member to take care of the woman's young daughter.

On Valentine's Day, Neela falls under the spell of Dr. Brenner, Banfield refuses to give up on having a baby, and Dr. Carter (NOAH WYLE) makes a surprise return to the ER.

Banfield and her husband look into adoption, while Carter adjusts to a changed ER. Sam's mother (guest star AMY MADIGAN) comes into the ER in an altered state of mind.

The story of County General is revealed as a camera crew interviews the staff for a documentary on emergency medicine. Noah Wyle and Amy Madigan ("Grey's Anatomy") guest star.

The ER doctors struggle to save two transplant patients when the transplant organs are stranded at the airport. And Carter gets a surprise visit from his old mentor Dr. Benton.

It's Neela's last day at County General and everyone in the ER seems to have forgotten that she is leaving. Meanwhile, Brenner has an epiphany about his troubled past.

The ER doctors and nurses help out at Camp Del Corazon, a camp for kids who have had open-heart surgery, working alongside the camp counselor (guest star TOM ARNOLD).

In the series finale, Dr. Carter opens a new medical facility for the underprivileged in Chicago and some old friends from County General all come to show their support.

As "ER" comes to a close, this hour-long retrospective takes a look back at past seasons with clips from the most memorable episodes and interviews with many of the series' stars.