Absolutely, Positively — Jayne Ann Krentz

Molly Abberwick, trustee of her late father's foundation, is furious with her new consultant, scientist-philosopher Dr. Harry Stratton Trevelyan. Harry is brilliant, sexy, and absolutely impossible-- and his outrageous suggestion of a scientifically inspired affair with her is positively the last straw .... Besides, Molly's got a much more serious problem; she's become the target of a stalker whose sinister pranks are swiftly escalating into violence. Only Harry, of all people, seems to comprehend the true nature of the threats against his alluring boss. As a dangerous predator closes in on Molly, the enigmatic Dr. Harry seizes the day to reveal himself in a totally unexpected light ....