Rose Early is searching for her missing sister Juan. The only clue she has is a horror novel with her sister's notes in the margins. The author of the book lives only a few minutes away and Rose can't resist seeking him out. She understands why the book affected her sister: the author creates an evil so palpable it shakes even skeptical Rose.

Vic Drummond, the writer, knew Rose's sister and agrees to help Rose find her. Rose expected him to be reclusive and strange, but she didn't expect him to be quite so... attractive. As their search intensifies, Rose finds herself incurable drawn to Vic, but it seems to Rose that their feelings for each other are being influenced by some outside force - she knows love at first sight doesn't exist.

As they come closer to finding Joan, Rose and Vic journey from the local church to a mysterious sex club whose members dress in demon costumes. The more they learn about what Joan was doing in the days before her disappearance, the more questions they have, until Rose must decide. Does she believe in real evil? And does she believe in real love?