In this clip from an "unprecedented Gossip Girl event," which will happen Wednesday, January 9 in the form of an all-new Gossip Girl episode, Serena has it out with Blair over a rumor that started when S tried to cover for B... could it have to do with a pregnancy test? Check it out...

This may end up being the last episode of Season 1, as the writers' strike continues with no end in sight. At least it looks like it will be a good one. Follow the jump for another sneak peak from "The Thin Line Between Chuck and Nate," when Dan trying to profess his love for Serena ...