ER

In the overburdened emergency room of the urban Chicago teaching facility County General Hospital, a Level One Trauma Center, the difference between life and death rests on split-second decisions -- and the pressure, joy and guilt are often overwhelming. On staff are Dr. Abby Lockhart who made the professional transition from nurse to doctor and is making a serious effort to turn her personal life around; Dr. Gregory Pratt now an attending, whose checkered background won't stop haunting him.

Moretti (recurring guest star STANLEY TUCCI) continues to institute new measures that cause many of the emergency room doctors to despise him. When a teacher and student come into the emergency room after a car crash, Morris and Sam are shocked to find out why they were together. Abby treats a patient with a simple stomachache, but she learns that he has a much bigger problem. Meanwhile, Neela can't wait to get released from the hospital.

When a teenage wrestler comes into the emergency room with severe vomiting, Pratt quickly tries to solve the problem, but he finds out that the cause is much more serious. While working in the intensive care unit, Gates attempts to help a young kid with a deadly disease. Meanwhile, Abby and Morris jump in to save two volunteer cops brought in with gunshot wounds.

County General Hospital is turned into a beauty parlor for a day when a gracious former patient provides free beauty treatments. Meanwhile, Abby becomes distraught when her child is brought in after taking a serious fall off a jungle gym. Gates makes a baseball dream come true for a young boy with a terminal illness. And Pratt tries to stick up for his brother but seems to just make matters worse.

Moretti (recurring guest star STANLEY TUCCI) decides that Gates has done an impressive job in the intensive care unit and is now ready to return to the emergency room. Meanwhile, Neela learns how to manage people when she is assigned to mentor a gifted young intern. With his girlfriend away, Morris has a hard time resisting the ladies. And Abby struggles to keep her life together without Kovac (former series star GORAN VISNJIC), who has gone to Croatia.

When Moretti (recurring guest star STANLEY TUCCI) brings in a new attending physician, Skye Wexler (recurring guest star KARI MATCHETT), to help with the workload, Morris and Pratt find the time to cram for their medical board examinations. Meanwhile, Sam and Abby treat an attention-hungry young woman who comes into the emergency room with elusive symptoms. And an intern, Harold (recurring guest star STEVEN CHRISTOPHER PARKER), tries to get tips from Neela on how to please the ladies.

In an effort to be more environmentally conscious, Morris buys an energy-efficient smart car. Meanwhile, Abby and Pratt try to treat a fussy baby but disagree on the diagnosis. And Abby falls back into old habits and gives into temptation while her husband is in Croatia. Recurring guest star REIKO AYLESWORTH appears as Julia Dupree.

Gates and Julia (recurring guest star REIKO AYLESWORTH) nurture their newfound romance but are soon interrupted by a troubled phone call from Gates' ward, Sarah (recurring guest star CHLOE GREENFIELD). Meanwhile, Abby continues to be off her game, and the other doctors are starting to take notice. Harold (recurring guest star STEVEN CHRISTOPHER PARKER) saves the day in a critical situation -- and still makes his date. And Kovac (former series star GORAN VISNJIC) surprises Abby by returning home a day earlier than expected. Recurring guest star STANLEY TUCCI appears as Moretti.

When Kovac's (former series star GORAN VISNJIC) brother visits from Croatia, Abby feels crowded in her own home. Meanwhile, Gates starts to experience the pressure of fatherhood after Sarah (recurring guest star CHLOE GREENFIELD) decides to have a sleepover with her friends. And Pratt becomes upset when a new temporary emergency room chief is named. Recurring guest star KARI MATCHETT ("24") appears as Skye Wexler.

In this special 300th episode, Kovac (recurring guest star GORAN VISNJIC), Abby and baby Joe quickly make plans to go to Croatia after Kovac's father unexpectedly passes away, yet something still seems off with Abby. At the ER, a husband (guest star PETER FONDA - "3:10 to Yuma") rushes in when he hears about his wife#s car accident and is shocked to meet someone from his past. Meanwhile, Julia (recurring guest star REIKO AYLESWORTH) decides to hold a service to bless the ER and the patients that have been lost.

When a young woman comes in with a badly hurt ankle, Sam is shocked to learn how much they have in common. Jeanie Boulet (former series star GLORIA REUBEN - "The Agency") rushes into the ER after her son takes a fall during gym class. Meanwhile, when the higher-ups at the hospital don't take him seriously, Pratt finds himself wanting to quit his job. Recurring guest star KARI MATCHETT ("24," "Heartland," "Studio 60 on the Sunset Strip") also makes an appearance.

Abby checks out of rehab and makes her way back to the ER, but she finds herself being questioned by the other doctors. And when multiple victims of a fire come into the ER, Abby thinks that one of the little girls is suffering from LCA, a degenerative eye disorder. Meanwhile, Harold (recurring guest star STEVEN CHRISTOPHER PARKER) finds new confidence after a big night with Neela's cousin.

Pratt gets cold feet when Bettina (recurring guest star GINA RAVERA) tries to take their relationship to the next level. Neela joins the Ortho's hockey team and is shocked to see who their opponents are in the first game. Meanwhile, a prison doctor comes into the ER after trying to save a young boy from a freezing lake. After revealing to Julia (recurring guest star REIKO AYLESWORTH) that he gave lethal injections to criminals on death row, she tries to help him get rid of his guilt. And Gates gets irritated with Sam when she undermines his decisions.

Pratt and Dr. Brenner (recurring guest star DAVID LYONS - "Sea Patrol") get off to a rocky start when Brenner refuses to teach the interns. Gates treats a young transplant patient with major heart trouble. Abby contemplates telling Kovac (former series star GORAN VISNJIC) the truth about her affair as she heads for Croatia. And Sam finds out that Gates and Julia (recurring guest star REIKO AYLESWORTH) have broken up.

Neela has a strange daydream during work after pulling an all-night shift. Plus, she makes a quick decision about a patient with a torn aorta (recurring guest star AIDA TURTURRO - "The Sopranos"). Sarah's (recurring guest star CHLOE GREENFIELD) grandfather (guest star BILL BOLENDER - "CSI: Miami," "Alias," JAG") is rushed to the ER after collapsing during a game of air hockey. And Gates tries to let Sam know that he is serious by sending her flowers.

Neela is upset after she finds out the aorta surgery on Sheryl Hawkins (recurring guest star AIDA TURTURRO) has caused an infection. While treating a severely beaten Korean teen, Abby discovers an even more serious condition. Kovac (former series star GORAN VISNJIC) struggles to forgive Abby for her indiscretion. And Dr. Brenner (recurring guest star DAVID LYONS) continues to ruffle feathers in the ER.

Pratt decides to fight for his relationship with Betina (recurring guest star GINA RAVERA) despite her reluctance. Neela treats a young injured couple, but when one of them pulls a gun (guest star JOSH STEWART - "Dirt"), she quickly finds out about their criminal status. Abby sees signs that her relationship may be over and it scares her.

Morris meets with the hospital psychologist for a debriefing after his traumatic run-in with the jewelry thieves. Neela is frustrated when Sheryl Hawkins (recurring guest star AIDA TURTURRO) must go in for a fourth surgery to fix the infection. Meanwhile, Abby struggles to make a decision after she is offered a new job.

In an explosive season finale, a mysterious patient (guest star STEVE BUSCEMI - "Fargo," "The Big Lebowski," "The Sopranos"), with very mysterious visitors, comes into the ER.