George Clooney returning to ER

George Clooney has reportedly agreed to return to ER, the medical drama that made him famous, for the show's final season. Insiders say that ER co-creator John Wells has ordered a closed set to keep the Hollywood actor's appearance secret. There are no details about how many episodes Clooney will film, and neither the show's networks nor the actor's publicist has commented about the reports. Clooney's character Doug Ross was last seen on ER in 2000 during a remote lake scene with Juliana Marguilies. SOURE: PEOPLE