Melissa Roxburgh has joined the pilot for the planned spinoff of The CW's Supernatural, according to The Hollywood Reporter. Once subtitled "Tribes" but now subtitled "Bloodlines," the backdoor pilot will air as a regular episode of Supernatural on April 29.

Roxburgh, who has appeared on Arrow and in the Diary of a Wimpy Kid films, will play Violet, a werewolf in a Romeo & Juliet-esque relationship with Nathaniel Buzolic's character, who is a shapeshifter.

Penned by Supernatural writer/producer Andrew Dabb, the pilot involves mafia-like monster families who secretly run the Chicago underworld and the new hunter (played by Lucien Laviscount) who’s trying to rid the city of all of its supernatural elements. Dabb will executive produce alongside Supernatural creator Eric Kripke and series veterans Robert Singer, Jeremy Carver and McG. Carver serves as showrunner, while Singer will direct the pilot. The cast also includes Sean Faris, Danielle Savre and Stephen Martines.