Leighton Meester as Blair Waldorf, Penn Badgley as Dan Humphrey, and Blake Lively as Serena van der Woodsen in a dream sequence from the 100th episode of "Gossip Girl."

Leighton Meester as Blair Waldorf, Penn Badgley as Dan Humphrey, and Blake Lively as Serena van der Woodsen in a dream sequence from the 100th episode of "Gossip Girl."