There's no word on what prompts her character Juliet Sharp's return, but she was last seen in Season 4 of the show, when she dated Nate (Chace Crawford) and devised a plot to bring down Serena (Blake Lively), who had had an affair with Juliet's brother Ben (David Call).
Cassidy is currently starring on The CW's Arrow.
Gossip Girl's series finale will air Dec. 10 on The CW. Why do you think Juliet's back in town?
- Juliet Sharp