Katherine Heigl made a visit to The Late Show with David Letterman Monday, and complained (semi-jokingly) about returning to the set of Grey's Anatomy last week.

“Our first day back Wednesday was - I’m going to keep saying this because I hope it embarrasses them - a 17-hour day,” she said, “which I think is cruel and mean.”

“It was actually kind of really great to be back,” she added after.

“All my friends are there and at this point, they’re sort of like family, although it was a little weird because [T.R. Knight]’s not there anymore.”

Katherine Heigl remained tight-lipped about the fate of Izzie.

“You last saw Izzie, you know, flatlining,” she said.

“So, I won’t give it away but, you know, I’m there so I’m either there as a ghost, on the other side or I survived a disease no one survives.”

“I’m guessing that if you’re working 17 hours, that means you’re not dead,” Letterman said. Heigl’s reply: “What if, however, Dave, I was in a bed in a coma for 17 hours, they could do that ...” Dave responded if they did that to him, no one would know the difference.

Ba-dum-ching.

Heigl said she hopes Grey’s Anatomy, which returns to ABC on September 24, will stick around for a while - with her on it: “We have another two years, I think, at least in the contract ... Hopefully the show goes, you know, ER time, which would be cool.”

Indeed. Here's Katherine's interview on The Late Show ...

[video url="http://www.tvfanatic.com/videos/katherine-heigl-on-letterman/" title="Katherine Heigl on Letterman"] [/video]

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.