E.R. is one of the most popular and successful television shows of the ’90s, and it's only fitting to have a star-studded reunion. Jimmy Kimmel attempted to do just that when he had George Clooney on his show Tuesday night. Unfortunately, Clooney was the only cast member who showed up. As the TV host explained to Clooney, everyone else was busy.

“This was kind of a last-minute thing, and we had some trouble getting the whole cast of E.R. to come,” Kimmel said. “[Julianna Margulies] was filming The Good Wife, so she couldn’t make it. [Noah Wyle] wanted to be here, but guess he had a thing with his family, Taco Tuesday. Eric LaSalle had jury duty.”

Though one person who wasn’t busy: Hugh Laurie. Dr. House himself showed up, transforming the would-be E.R. reunion into one for Tomorrowland. Laurie and Clooney both tried to shake off their TV doctor rust.

“He’s going into supraventricular tachyarrhythmia,” Clooney said.

“I don’t even remember what that is!” Laurie said.