A frantic Sam and too-calm Luka report diabetic Alex missing after he runs away to find his father. Acting on information from the police they follow a lead to Iowa, then eventually head for Colorado. As they travel, they discuss their relationship, slowl

A baby's life is endangered when the surrogate mother refuses a C-section. The biological parents, Ray, and Dr. Coburn disagree over the surrogate mother's treatment. Abby makes a difficult diagnosis on a young boy with a rare illness. Pratt is reunited w

THERE'S A NEW NURSE IN TOWN AND SHE MEANS BUSINESS - KRISTEN JOHNSTON ("THIRD ROCK FROM THE SUN") JOINS ER - The ER is shaken up when new nurse manager, Eve (Kristen Johnston) enforces her strict and efficient new procedures. Kovac (Goran Visnjic) and Sam (Linda Cardellini) struggle to find some civility with each while working the same shift. Abby (Maura Tierney) treats a breast cancer patient who is having a hard time coming to terms with her condition. Parminder Nagra, Mekhi Phifer, Shane West and Laura Innes also star.

A PATIENT WAKES UP FROM A NINE YEAR COMA - A patient who has been in a coma for nine years suddenly awakens in the ER and Kovac (Goran Visnjic) struggles with whether he should reveal her the truth about her past. Abby (Maura Tierney) comforts Dr. Dubenko (Leland Orser) after he finds out some troubling news. New Nurse Manager Eve (Kristen Johnston "3rd Rock from the Sun") makes waves in the ER as she implements her strict methods. Also starring Laura Innes, Maura Tierney, Mekhi Phifer, Laura Cardellini, Shane West, Parminder Nagra and Scott Grimes

Pratt (Mekhi Phifer) gets a wake-up call when the new attending (John Leguizamo) poses as a patient to test the knowledge of doctors in the ER. Meanwhile, Kovac (Goran Visnjic) bonds with the former coma patient and contemplates bending the rules for her. A breast cancer patient convinces Abby (Maura Tierney) to get her first mammogram. Pratt's father Charlie (Danny Glover) tries to convince his son that he has turned his life around. Kristen Johnson, Laura Innes, Parminder Nagra, Scott Grimes, and Shane West also star.

There’s monkey business in the ER as Clemente, Abby and Neela treat an infant chimpanzee. Pratt has a painful failed attempt at reconciliation with his father. Eve promotes Sam, then forces her to be involved as she fires Haleh. Ray discovers Zoe has chla

EMOTIONS RUN HIGH WHEN A DIFFERENCE OF OPINION MEANS LIFE OR DEATH-JOHN STAMOS GUEST STARS--Neela (Parminder Nagra) gets all dolled up for Gallant's homecoming (Sharif Atkins) and her co-workers seem to take notice but, her plans change when she receives a call from Iraq. Meanwhile, Abby (Maura Tierney) is caught in the middle between Kovac (Goran Visnjic) and Clemente (John Leguizamo) when they disagree on how to save a patients life. When a cop and a little girl become victims of a shoot out, Neela is plagued with the decision of whether or not she should save the shooters life.

For Neela, what begins as a routine ride-along with Gates and Zadro turns into a defining day when a plane crashes over Chicago. As Clemente manages the trauma in the ER, Pratt joins Neela on-scene. Luka and Abby wake up together at Luka’s, but the crash soon takes them back to work, where the tension between Luka and Clemente continues. As patients flood in, Sam recalls Haleh when extra nurses are needed, and earns Eve’s approval. Luka and Abby care for a patient with severe facial injuries while Pratt struggles to save a patient with a heart injury. Ray’s youthful friend returns and creates a nuisance. As the day ends, Luka and Abby talk, and awkwardly decide to stay “just friends” while Neela has a welcome, and overdue, visitor.

As the tension between Kovac and Clemente heightens, two doctors make their feelings known, while another stands up for himself. The ER comes together for an unexpected and surprising celebration.

On Christmas Eve, one doctor heads up and one nurse heads out of the ER. Meanwhile, while there are festivities afoot, carols to be sung, and Santa has come to town, not all is merry and bright. But romance is in the air, leading to a surprising exchange of Christmas gifts.

Two weeks after Christmas, Luka and Abby struggle with a decision about whether to keep the baby, which Luka wants but Abby is unsure she is ready to have. Abby treats three patients, each of whom triggers a flashback in which they discuss her fears, and what each of them wants. Luka discovers Neela has consulted with Dr. Coburn about Amanda, a pregnant, and very religious, 15-year-old girl, without first presenting to him. When Amanda’s parents refuse an abortion, the two differ over her care and whether Luka is influenced by his Catholicism. Later, Abby discusses her pregnancy with Coburn, and makes an appointment to see her. Luka removes Neela from Amanda’s case, before suggesting a termination option that Amanda can accept. Kerry takes a fall on the ice, injuring her hip, which may have to be replaced. Ray begs Kerry for time off to join his band in LA for a gig, but the band decides to move on without him. Clemente gets a visit from the two detectives looking for the missing Jodie, and later pays a quick visit to the drug lock-up for a little help. After her appointment, Luka finds Abby near the lake. He tells her they can still be together despite her choice, and she tells him she wants them to have the baby.

With Luka eager to get home, Clemente AWOL and Kerry temporarily off her feet, Dubenko volunteers to cover the ER briefly, but quickly becomes involved with a septic patient and her husband, who is unwilling to accept she will not improve. He soon finds himself at odds with both the ER and ICU staff over an appropriate course of treatment. Abby’s excitement over her pregnancy means no sleep for Luka, and they head out for a bit of early shopping, and some dressing-room fun. Neela gets surgery as an elective, but is shocked to learn that rather that finishing his training in the US, Michael plans to return to Iraq. Ray helps Zoe escape to live with her sister when she arrives in the ER after a beating by her father, and Pratt fakes a blood test to help Darnell avoid arrest.

Emmy-winner James Woods guest stars as a Dr. Nate Lennox, a former professor of biochemistry with ALS who was Abby’s early medical school mentor. As we follow the progression of his disease in reverse via a series of flashbacks, a different ER doctor treats him at each stage beginning with Neela as he must face the need for oxygen full time moving backward to Luka in the early stages. In the present, Lennox, now able to move only his eyes, and equipped with advance communication technology, is admitted with pneumonia. As Ray, Sam and Luka begin limited treatment under the proxy of his attendant, Abby believes Nate has communicated his own wishes, leading to a struggle to determine what course of action should be taken, and how long to fight the inevitable.

An unexpected visitor puts Clemente in the middle of a domestic dispute, and things don’t look good. As the police sort out events, Luka, Abby and Sam try to save the victim in the aftermath of a shooting. Luka and Abby await important news about the baby. Pratt finds himself the center of unexpected attention at a fundraising event.

ER revisits Dr. John Carter, to see what he’s been doing since his departure from County. Now in Darfur, Dr. Carter and his colleague Dr. Dakarai work alongside relief workers to treat famine victims. Back in Chicago, Luka and Kerry differ over Clemente’s next step while Pratt and Neela treat a hit-and-run victim. But what’s that list Luka’s making, and why does Abby think it’s so funny?

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.

Oscar-nominated Iranian actress Shohreh Aghdashloo guests stars as a Turkish mother whose daughter is brought to the ER close to death following a knife attack. Luka and Abby must struggle both to keep her alive and to understand the reasons behind the attack. But when surgery is delayed, will Luka put his trust in a risky procedure that might save her life? Sam makes a life-altering decision, while Neela’s first conference presentation doesn’t go exactly as planned.

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 (guest star Diane Ladd), 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, but soon finds his eyes opened to the need all around him. Debbie attempts to persuade Dakarai to seek treatment for his illness. Carter, Pratt and Dakarai find themselves in the middle of the conflict when a man and his pregnant wife arrive at the camp needing treatment, with trouble not far behind. Events force Pratt and Dakarai to make a dangerous journey.

Clemente’s behavior grows more and more erratic, forcing Luka to take a stand. Pratt returns from Africa, and works with Luka, Abby, and Sam on the case of a father and two sons who appear to have been beaten by gang members, but soon, Pratt learns the real story. Morris and Albright throw off some sparks. Dubenko has good news for Neela, but will two visitors bring something different?

Season Finale: In the aftermath of the tragedy befalling the ER, it’s a seemingly ordinary day with the usual collection of patients. But soon, the day becomes anything but ordinary as two prisoners intent on escape come to the ER for treatment, along with a hidden conspirator. Their desperate actions place one doctor in harm’s way, and forces one nurse to become a tool in their plan. Soon, gunshots ring out, another doctor hits the floor, and a staff member’s life is in jeopardy. The medical staff rush to the aid of the injured and quickly discover one of their own is missing!