'Unsane' Trailer: Steven Soderbergh's Latest Finds Claire Foy Battling Stalker

The 'Crown' star is involuntarily committed to a mental institution, where she soon begins to question what is real or a figment of her imagination.

Claire Foy may have played Queen Elizabeth, but the actress is ready to take the crown for being Unsane in the first trailer for the thriller, released Monday.

In the preview for the Steven Soderbergh film, a young woman (Foy) begins receiving text messages from a stranger named David, forcing her to seek out support groups that aid victims of stalking. Soon she begins seeing her stalker everywhere and starts to question her sanity.

“I’m alone in a strange city and I never feel safe,” Foy’s character tells someone at a treatment center.

After signing some paperwork, the woman finds herself involuntarily committed to a mental institution. She soon begins to question whether her stalker, who appears as a worker in the hospital, is real or a figment of her imagination.

Soderbergh directed the film from a script by Jonathan Bernstein and James Greer. The Oscar winner reportedly shot the feature on an iPhone and will self-distribute the film through Fingerprint Releasing via Bleecker Street — the same strategy he used for Logan Lucky earlier this year. Joshua Leonard, Jay Pharaoh, Juno Temple, Aimee Mullins and Amy Irving also star in the film.

Unsane is set to hit theaters on March 23.