A group of graduate students engage in an experiment they won't soon forget in the third trailer for Lionsgate's The Quiet Ones. John Pogue (Quarantine 2: Terminal) directs this upcoming thriller which follows a university professor (Jared Harris) who is trying to study the dark mind of a troubled student (Olivia Cooke), in an attempt to create a poltergeist from her negative energy. Sam Claflin and Erin Richards co-star in this intense ride from Hammer Films, in theaters April 25.

A university student (Sam Claflin of The Hunger Games: Catching Fire) and some classmates are recruited to carry out a private experiment -- to create a poltergeist. Their subject: an alluring, but dangerously disturbed young woman (Olivia Cooke of Bates Motel). Their quest: to explore the dark energy that her damaged psyche might manifest. As the experiment unravels along with their sanity, the rogue PhD students are soon confronted with a terrifying reality: they have triggered an unspeakable force with a power beyond all explanation.