Actress Olivia Williams has joined the cast of The Seventh Son for Warner Bros. and director Sergey Bodrov (Mongol).

The project is adapted from Joseph Delaney's young adult novel series, about a young man who learns he has magical powers because he is the seventh son of a seventh son. He learns his magical craft from a "spook." Jeff Bridges, Ben Barnes, Alicia Vikander, Julianne Moore, Kit Harington, and Antje Traue also star. It isn't known what character Olivia Williams will play.

Sergey Bodrov is directing The Seventh Son from an adapted screenplay by Matt Greenberg. Thomas Tull, Basil Iwanyk, and Lionel Wigram are producing, with Jon Jashni and Alysia Cotter executive producing. It isn't known when production will begin on The Seventh Son.