'House' Finale: Olivia Wilde Returns For Final Episode And More Casting News

"House" is on its way out, but according to TVLine the Fox medical drama has a surprise ending.

Olivia Wilde's character Thirteen is returning for the series finale (Mon., May 21 at 9 p.m. ET). The actress left the series in October after being fired by House (Hugh Laurie) back in October.

Wilde originally left the series to pursue her film career, working on movies like "Blackbird," "People Like Us," and "The Longest Week," all out this year.

Janel Parrish will be a series regular on "Pretty Little Liars." A recurring guest star since Season 1, Parrish is set to appear regularly as Mona, otherwise known as the mysterious "A," in Season 3 of the ABC Family drama. [THR]

"Smallville" actress Allison Mack lands a role in FX's "Wilfred." Mack is back. The actress, who has mostly been focusing on stage work since the series finale of "Smallville" in 2011, has been cast in "Wilfred" as a biochemist and girlfriend to Elijah's Wood's character in the comedy's second season. [TVLine]

"William & Kate" star Camilla Luddington will play a fairy in HBO's "True Blood." Luddington is ditching her royal duties for fairy wings. The star of Lifetime's royal wedding made-for-TV movie "William & Kate" is headed to HBO's vampire drama alongside Anna Paquin and Stephen Moyer for the show's fifth season. [THR]

Stepfanie Kramer will guest star on "CSI: Crime Scene Investigation." In April, former "Hunter" co-star Stepfanie Kramer will appear on the CBS crime drama as Vivian Brenston, mother and attorney to Zack, a boy who is constantly in trouble with the law and learns he is part of a set of triplets after winning a trip to Las Vegas. [THR]