Inspired by the legend of Faust and told in alternating timelines, sixteen-year-old Roan arrives at Mill House as a ward and discovers she is connected to an ancient evil secret, while, centuries later, seventeen-year-old Zoey explores the dwelling's ruins and soon realizes she is not alone.

The present: Photography enthusiast Zoey and her best friend, Poulton, run away from home to explore Meddwyn Mill House. But are they really alone in the house? 1851: Roan arrives at the Mill House as a ward-- one of three, all with something to hide from their new guardian. When Roan learns that she is connected to an ancient secret, she must escape the house before she is trapped forever. 1583: Hermione, a new young bride, comes to the wilds of North Wales where her husband plans to build the largest water mill and mansion in the area. Three women, centuries apart, drawn together by one Unholy Pact. A pact made by a man who, more than a thousand years later, may still be watching.... -- adapted from jacket