A few days ago, Bones creator Hart Hanson leaked an exciting piece of news via his Twitter account (follow him @harthanson): After years of scheduling conflicts, they had finally arranged to have Emily Deschanel's sister Zooey guest star on an episode of the show.  The studio confirmed the news with the below press release, and the episode will air soon on Sky1!

Bones: The Deschanel SistersBones: The Deschanel SistersZooey Deschanel, star of the romantic comedy "(500) Days of Summer" and sister of Bones' Emily Deschanel, will guest-star in "The Goop on the Girl," a special holiday-themed episode of Bones.

In this first-ever on-screen pairing of the Deschanel sisters, Zooey Deschanel plays MARGARET WHITESELL, a distant relative of DR. TEMPERANCE BRENNAN (Emily Deschanel). When Brennan's father, MAX KEENAN (guest star Ryan O'Neal), makes contact with Margaret, he invites her to spend Christmas with him and his daughter. Meanwhile, Brennan and BOOTH (David Boreanaz) investigate the death of a man dressed as Santa Claus who was blown up after a botched bank robbery.

Zooey Deschanel's film credits include "All the Real Girls" for which she received an Independent Spirit Award nomination for Lead Actress; "Elf" with Will Ferrell; "The Hitchhiker's Guide to the Galaxy" with Sam Rockwell, Mos Def and John Malkovich; "The Assassination of Jesse James by the Coward Robert Ford" opposite Brad Pitt and Casey Affleck; "Gigantic" with Paul Dano; and "Yes Man" opposite Jim Carrey. She will next be seen in the film "Your Highness" opposite Danny McBride, James Franco and Natalie Portman. In addition to her work on-screen, Deschanel and singer-songwriter M. Ward perform together as the musical duo She & Him. The pair has earned rave reviews for their debut album, "Volume 1."

The milestone 100th episode of Bones, directed by Boreanaz, will air in spring 2010.