Vivien (Katie Douglas), 16, is trapped in a prison-like boarding school called The Vestalis Academy, where she keeps to herself and sticks her neck out for no one.

That is, until she's reunited with Sophia (Celina Martin) -- a former friend who betrayed her. Together the girls embark on a dangerous search to uncover the horrifying truth behind their imprisonment. Soon running for their lives, the girls must save themselves or die trying.