Blake Lively to Star in Murder Mystery From 'Big Little Lies' Author (Exclusive)

Chris and Paul Weitz are producing CBS Films' adaptation of 'The Husband's Secret.'

Blake Lively's got a secret.

The Gossip Girl grad will star in CBS Films' adaptation of The Husband's Secret, the New York Times best-seller from Big Little Lies author Liane Moriarty.

Chris Weitz, Paul Weitz and Andrew Miano are producing via their Depth of Field shingle. Lively will also executive produce the adaption, which is currently out to potential directors.

Lively will play Cecilia Fitzpatrick, a chronic perfectionist whose suburban bubble is burst when she finds a note from her husband addressed to her with instructions to open it in the event of his death. But he's still alive. She then discovers a secret that her husband has been keeping from her for years, which leads her to realize that her life is built on a foundation of lies and murder.

Mark Ross and Alex Ginno are overseeing the project for CBS Films, which acquired the book in 2013, prior to the release of the hit HBO series. But with the success of the Reese Witherspoon-fronted series (and now Lively's attachment), the studio and producers are making The Husband's Secret a priority.

"Liane Moriarty has established herself as one of the defining voices of the modern woman, and Blake Lively's unique combination of vulnerability, strength and extraordinary talent makes her the perfect actress to realize Moriarty's creation," said CBS Films president Terry Press.

Moriarty's other works are also on the Hollywood docket. Big Little Lies stars Nicole Kidman and Witherspoon have optioned the 2016 novel Truly Madly Guilty, while Sony's TriStar owns the rights to What Alice Forgot, which at one point had Jennifer Aniston attached to star.

Lively was last seen battling sharks in The Shallows and 1940s movie starlets in Woody Allen's Cafe Society. She is repped by WME, Management 360 and Jackoway Tyerman.