George Clooney will return to ER

The cat is out of the bag now. George Clooney will come back to the show that launched his career: ER.

Clooney’s Dr. Doug Ross was last seen on ER in 2000, a year after taking off to make movies full-time, to help tie up the storyline for Julianna Margulies’ departing character, Nurse Carol Hathaway, who had twin daughters with Clooney’s Dr. Doug Ross.

Speculation is that Clooney and Margulies will reunite as “part of an effort to wrap up all of the original characters’ story lines” and that their episode will air toward the end of February, during sweeps.

ER co-creator John Wells has ordered a closed set to keep Clooney’s appearance under wraps.

Clooney is the most famous ER alum and Wells has always wanted him to return for the show’s last season. The stalwart Thursday-night drama’s 15th season was extended by an extra 3-4 episodes by NBC executives last week

It’s not known how many episodes will feature Clooney as the show films its final season.

Clooney, himself, denied reports last March he was returning.