Incubus.
"Galen is an ordinary, peaceful small town. Until horrendous terror strikes ... and strikes again and again, each time claiming a female victim in a fashion too hideous to contemplate. Julian Trask, student of the occult, is used to thinking the unthinkable. As he works towards the solution of the soul-searing mystery, Galen trembles in mortal dread. For no woman is safe from the lethal lust of THE INCUBUS."