" Ex-Husbands and Wives " is the 21st episode of the third season of , which originally aired on May 10, 2010. The episode serves as the penultimate chapter of the season, escalating the tension surrounding the return of William van der Woodsen and the unraveling of his deceit. Primary Plot: The William van der Woodsen Conspiracy
: As the truth comes to light, Jenny tips off William that the group is on to him. William manages to flee New York just as the police close in, but not before telling Serena he truly loves her and Lily. Romantic Arcs and Ultimatums [S3E21] Ex-Husbands and Wives
: In the aftermath of her father's departure, Serena finds comfort in Dan, leading to a moment of closeness between the two exes. Jenny Humphrey’s Descent " Ex-Husbands and Wives " is the 21st
: Chuck and Jenny team up to uncover the truth about Lily’s medication. They eventually enlist Blair, who uses a black-tie event to trap Dr. Holland—the neighbor William used to write fake prescriptions. William manages to flee New York just as
: It is discovered that Lily was not actually sick; William had been providing her with unnecessary medication to keep her dependent on him and to win her back from Rufus.