iss and Kill (1969)

The nice-guy blues
The nice mild man named Edward Tollman had a problem. His lovely wife was missing, and he wanted her back -- fast. So he went to a fellow whose specialty was solving problems like that -- a very private detective called Barney Burgess. Burgess' methods were not pleasant -- but they got results. Burgess was used to sordid scenes and secrets. But after four quick corpses, a wild ride to Mexico, and a blonde sex bomb who threatened to blow the case wide open at the first wrong move, Barney began to wonder how such a nice guy got him into something this nasty... .

Ghostwritten by Charles W. Runyon his third and last contribution to the series. (Death & Ghosts F.Nevins 1998). A tornado-paced fable of pursuit and menace complete with sex, sadism, machismo and a psychopathic monster. When a young Chicago housewife vanishes after returning from a solo tour of Mexico, her distraught husband and a local PI take up the trail and soon discover that everyone else on that tour has either disappeared or suffered a violent death.
About halfway through the book the action shifts to south of the border where Runyon had spent many years, and the two urban male protagonists, joined by a woman photographer from St. Louis, become instant experts at guerrilla warfare against professional killers. But neither this implausible development nor the recycling of tough guy fiction's most overused climactic "surprise"� diminishes the pure headlong storytelling drive that makes Runyon's ultimate men's-mag adventure impossible to put down unfinished. (Nevins)

We also like to mention the existence of a 1960 unrelated book with the same title  ... Kiss and Kill by that other ghostwriter Richard Deming. The cover text reads: "Here was a deadly version of the worlds oldest profession". To be clear, Deming himself said in an interview to have written 10 books under the Queen-monicker and all are already accounted for, so this is just coincidence ... 

Right: Kiss and Kill - Richard Deming in 1960