Here--from the prolific author of the Isaac Sidel series and, most recently, the non-fiction Metropolis--the story of Sidney Holden, a Manhattan-based ""bumper, or hit man, who's nominally vice-president of a New York fur business but actually reports to a mysterious Swiss named Schatz, who lives in Paris. Holden kills on order, without regret--but then during one job in Queens, he finds that he has a witness, a little girl. This child, Barbara, is a Marielito, offspring of two Cuban no-goodniks shipped out by Castro; and thereupon Charyn sends Holden into the Cuban underworld as well as into the New York Mafia, with side-bar love interest in Fay, daughter-in-law of the crooked Queens District Attorney. But so frenzied and frantic is the mÃ‰lange here that at every other sentence you keep getting the feeling you've skipped something. Why the fur district and why the Marielitos and why Holden takes off for Paris every once in a while (other than perhaps because Charyn has a sizable following in France)--all these seem arbitrary questions: the book has a kind of forced, injected fizz that's supposed to float you over the manic disjunctiveness, but it doesn't. Holden and the others are neither funny enough to be comic, still enough to function as cartoons, nor deep enough to be credible. Kool-Aid Kops.