Scam and counter-scam on some seedy mean-streets in Queens, N.Y.--starting when Toby Silk, a college-educated ex-con (for pot-pushing) and half-likable ne'er-do-well, receives one of those ""Business List"" chain letters. (Mail $50 to the first person on the List; add your name to the bottom of the list; get two other people to do likewise; etc.) Toby, who's yearning to set up his own photographic studio and marry his girlfriend Kate (her parents disapprove), grabs the Business List Concept as his last best hope--sure that he'll be one of the lucky ones to actually make a profit. At his favorite local bar-and-grill hangout he ropes in enough Business List takers to move the chain quickly into second gear. And, to double his potential fortune, Toby pulls a fast one on one of the takers: a Gypsy named Willie thinks he's on the List, but Toby has substituted his own mother's name-and-address for Willie's on all the proliferating Lists. Smart Toby? No, not-so-smart Toby. Because Willie happens to be a man at the end of his tether: a failure in the Gypsy world of ""bajour"" scams, a man who can no longer control the two women (wife Rosie, cousin Maria) who live with him, a failure who's desperately in need of a big windfall. So, when the money does start rolling in, for Toby and some of the other chain-letter participants, Willie wants to know why he hasn't received a cent. And, when Toby shrugs him off, Willie becomes very violent indeed--getting Toby beaten up, then kidnapping girlfriend Kate. . . with all of the Business List cash demanded as ransom. Rush, author of a fetching comedy-intrigue, Durner's Spring (1980), doesn't quite propel this small, black-comic entertainment along with enough energy and snap. His wry, ironic prose sometimes indulges in rather strained allusions. (""The eventual result was a distribution system so oddly arranged, Elbridge Gerry would have smiled."") But the Gypsy-family sequences are darkly engaging, the Queens locales are solidly sketched--and, with a couple of okay twists at the end, this is a mildly tense, modestly amusing diversion for fans of hapless-criminal capers.