Jenna Fischer And John Krasinski Talk Steve Carell's Surprise Appearance At 'The Office' Wrap Party (VIDEO)

This past weekend, the cast of NBC's "The Office" invaded Scranton, Pennsylvania -- the city the show is set in -- for a wrap party thrown in their honor. Onscreen couple Jenna Fischer and John Krasinski both hit the late night talk shows Monday night and talked about their experiences, as well as the surprise appearance of one Michael Scott AKA Steve Carell.

Krasinski was hanging out over on "Late Show," where he talked about the big reveal. "We had an extra seat and our show-runner Greg Daniels said, '"What’s the extra seat for?'" Krasinski said. "And they introduced Steve, and I’ve never heard a sound like it. It sounded like a jet engine. ... We were at a baseball stadium and he came out and people went bananas.”

On "Late Night," Fischer said that the cast got to ride in a parade through the city before heading to that stadium for a Q&A session where Carell's arrival was a surprise to more than just the crowd.

"Some of the cast members didn’t even know he was coming, so it was like a huge surprise to us as well," Fischer said. "They had to really keep it on the down low so it didn’t leak out.”

Also being kept very on the down low is Carell's cameo appearance in "The Office" finale. News of this has gone back and forth several times already, but TVLine is confident in saying that he'll be making a surprise appearance for the big finale on May 16 at 9 p.m. ET on NBC.

"Late Show with David Letterman" airs weeknights at 11:35 p.m. ET on CBS. Catch "Late Night with Jimmy Fallon" every weeknight at 12:37 a.m. ET on NBC.

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