When seventeen-year-old Helena is sent to be a governess at Archfall Manor - a beautiful but crumbling manor house, perched at the edge of a causeway in the North Sea - she feels confident she will know how to deal with the esteemed but eccentric Cauldwell family who own it. But it quickly becomes clear that the Cauldwells are hiding more than Helena could ever have dreamed of.

A series of sinister events come to a head the night of a great storm, which washes away the only path back to the mainland - and reveals in the morning that there has been a murder... quickly followed by another.

Suspicions and paranoia quickly run rampant. Someone has dark motivations in mind - and a killer's instinct to enact them.

But the Cauldwell's aren't the only ones keeping secrets. Helena has a very important one of her own - and soon she begins to wonder whether forces beyond her control might be willing her to enact her own dark plan . . .

Just how far will she go to get what she deserves?