Gabriel Blackstone has an unusual talent. A computer hacker by trade, he is also able to enter the minds of others. But he uses his gift only reluctantly — until he is contacted by an ex-lover who begs him to find her step-son, last seen months earlier in the company of two sisters. And so Gabriel visits Monk House, a place where time seems to stand still, and where the rooms are dominated by the coded symbol of a cross and circle. As winter closes in, Gabriel becomes increasingly bewitched by the house, and by its owners, the beautiful and mysterious Monk sisters. But even as he falls in love, he knows that one of them is a deadly killer. But which one? And what is the secret they are so determined to protect?