Lili Reinhart is heading back into dark territory.

The Forbidden Fruits star has officially joined the cast of The Mannequin, an upcoming serial killer thriller from Sean Byrne, the director behind Dangerous Animals and cult horror favorite The Loved Ones.

According to Deadline, Reinhart will star alongside previously announced cast member Melissa Leo in what’s being described as a “twisted, intense, and propulsive serial killer procedural” built around two central characters.

Specific plot details are still being kept secret, though Byrne’s comments strongly hint at a deadly clash between Reinhart’s character and Leo’s mysterious role — which may involve the film’s killer.

“Lili has such a grounded, authentic screen presence that’s a captivating mixture of vulnerability, independence, intelligence, and courage,” Byrne said in a statement. “I honestly can’t think of a more committed and immersive screen pairing than Lili and the equally fearless Melissa Leo to take on a serial killer like no other.”

That last line becomes even more intriguing when paired with Byrne’s earlier description of the project.

“There have been other serial killer procedurals, but this is its own thrillingly deranged beast — twisted, intense, propulsive, and anchored by a fearless performance from Melissa Leo, building to a shocking twist you won’t see coming.”

Reinhart recently stepped deeper into horror territory with her femme fatale performance in Forbidden Fruits, while Byrne has already proven he knows how to craft brutal, psychologically unhinged killers through films like Dangerous Animals and The Loved Ones.

The Mannequin is being produced by William Woods and Maddy Falle for Page 12 Pictures Inc., alongside Kristian Moliere for Triptych Pictures.

Executive producers include Steven Schneider, Phil Hunt, Compton Ross, Charlie Kemball, and Jed Benedict for Sixth Dimension, as well as Reinhart and Catherine Hagedorn through Small Victory Productions. Melissa Leo also serves as executive producer.

The film is backed by Studiocanal’s genre label Sixth Dimension, with production scheduled to begin later this summer.