Title: O Brother, Where Bart Thou?
Air Date: December 8, 2008 at 12:00 AM PST
The Upper East Side mourns the loss of Bart Bass, and no one is more upset than Chuck, who blames Lily for his father's death. On the warpath, he uncovers an explosive secret about her past with Rufus. Serena and Aaron work through issues in their chaste relationship, and Serena is left with a dilemma over whether or not to travel with him to Argentina. In the midst of grief, an inconsolable Chuck seeks Blair's comfort.