Conan O'Brien seemed as surprised as his audience by the two guests stars on his stage Tuesday night. First, 'SNL' and '30 Rock' comedian Chris Parnell popped up in a sketch led by Deon Cole, but walked off the stage almost as unceremoniously as he arrived. Seconds later, though, Vince Vaughn took the stage with an exclusive new trailer for his summer comedy 'The Watch.' Didn't stay up to watch this live? Don't worry. We have it below.

Directed by Akiva Schaffer, 'The Watch' ran into a marketing obstacle when the tragic Trevon Martin case put a different spin on the idea of a neighborhood watch. Now trailers and clips for the Vaughn comedy – which also stars Ben Stiller and Jonah Hill – are playing up the film's eventual sci-fi angle. In fact, the first line of this new trailer is, “There is an alien invasion happening.”

The elongated gun gag at the end of the clip had me laughing, though.

Between this and the recent red-band trailer 20th Century Fox released for 'The Watch,' we have a pretty good idea what's in store when the movie comes out on July 27. The summer season's relatively thin on comedies, so 'Watch' has a great shot at cleaning up at the box office as audiences look for an alternative to superhero and comic-book properties.

Here's the exclusive new trailer for 'The Watch,' courtesy of Team Coco: