He's in our house. I never imagined that moving into our dream home, a beautiful Virginia Colonial, would unravel my life. The renovations are finally complete and I revel in the quiet moments, sipping coffee in the morning sun. But something is off. At first, it's little things — a creak in the floorboards, a misplaced item. I brush them off, chalking it up to the house settling. My husband Jacob is more distant, buried in late-night meetings and coming home reeking of whiskey and lies. But I love my life. So I let things go, sweeping them under the rug, because it's easier that way. That my husband is having an affair isn't an idea I'm ready to face or believe yet, either. Our four-year-old son Noah mentions his new friend, Billy, who lives in the walls. I dismiss it as a child's imagination. Maybe he's picked up on the strains in our marriage. As we're having dinner, Noah peers at his father. "Billy said he knows what you did." The idea my son knows about his father's transgressions sends a ball of rage rumbling in my gut . . . and a shiver of fear. Then one night I hear something — a soft thump in the attic. My heart pounds as I creep up the stairs, the silence of the house amplifying every sound. I reach the top, my breath hitching as I push open the attic door . . . Billy isn't imaginary. He's real. And he's living in our house.

AN EXHILARATING BLEND OF BREATHTAKING SUSPENSE WITH A SHOCKING FINAL TWIST.