Title: Carrnal Knowledge
Air Date: February 2, 2009 at 12:00 AM PST
Blair comes up with a slanderous plan to take down Rachel Carr. Chuck wakes up in a hotel with vague memories of a masked women and an insignia drawn on his wrist, and Nate and Vanessa try to help him fill in the missing pieces of his strange night. Meanwhile, Dan and Serena try to sustain their relationship against rumors of a student-teacher affair, and Rufus and Lily grow ever closer.