The New Girl cast has a new member - Zooey Deschanel's sister, but not the real-life one. The show has welcomed Mad Men star Linda Cardellini as the reel-life sister of Zooey Deschanel's character Jess.

Emily Deschanel, Zooey's real-life older sister, actually works in the same network as New Girl. She plays Dr. Temperance Brennan on the Fox crime drama-comedy Bones, but it seems like the sisters won't be working together on the same show just yet.

Linda Cardellini will be playing Jess' sister in a recurring role in the New Girl, when the show comes back to resume its third season next year. The actress is best known for her role as Lindsay Weir in the cult coming-of-age show Freaks and Geeks. It will actually be the first time she will be in a comedy role on TV since then, though she did play Velma Dinkley in the Scooby-Doo movie after. On the small screen however, she went on to play Samantha Taggart on the drama show, ER. She then recently made waves playing Don Draper's mistress on Mad Men last season, earning an Emmy nomination in the process.

The brunette is reportedly going to be a wild child on New Girl, and is rumored to become a love interest for the character Winston through the course of several episodes. She will start filming for the show this week, and her first appearance is slated to be in February.

Cardellini won't be the only guest star on New Girl this season however. TV stars Damon Wayans Jr. and Adam Brody, as well as Prince, will be making appearances as well. Past guest stars will be returning too. Jamie Lee Curtis and Rob Reiner, who play Jess' parents, will both be returning for a reunion of sorts, most likely with Cardellini in the fray. The sitcom is currently on hiatus, but will be back on the air in January.