Annabelle Wallis, who most recently appeared in Showtime’s Roger Ailes miniseries “The Loudest Voice,” has been tapped to star in James Wan’s top secret horror project, sources tell Variety.

Wan is tackling the movie this fall before he jumps into prep on the “Aquaman” sequel with Jason Momoa at the top of 2020. Plot details are currently being kept under wraps. Wan came up with the story with Ingrid Bisu, and he will produce through the Atomic Monster banner with Michael Clear. Details regarding who will pen the script are still being worked out.

The film, a recipient of the Independent California Film Rebate, is being independently financed through Starlight Media and Midas Innovation, who will retain distribution rights in China. New Line will handle the remaining distribution.

Wallis previously worked with Wan on “The Conjuring” spin-off “Annabelle.” That film became a huge success, grossing over $257 million worldwide from a $6.5 million budget.

Her other credits include include Universal’s “The Mummy” opposite Tom Cruise, Warner Bros.’ comedy “Tag” with Jeremy Renner, “King Arthur: Legend of the Sword,” “X-Men: First Class” and the British drama “Peaky Binders.”

She is repped by UTA, Untitled Entertainment and Jackoway Austen Tyerman Wertheimer Mandelbaum Morris Bernstein Trattner & Klein.