British writer White (Grandfather's Footsteps, p. 268, etc.) mixes domestic satire of a sitcom sort with a dark and gripping William Goldinglike tale of a deeply troubled boy--a teenager who teams up with a killer dog to avenge a bitter betrayal. White's England is a place of contrasts--between peaceful old villages and decaying tenements; concerned citizens and venal businessmen; pampered children and ones so mistreated that they're walking time-bombs--contrasts that she emphasizes with heavy-handed asides that may be true but increasingly irritate. The author's latest begins as two unmarried welfare mothers, sisters Kirsty and Sheralee Maggs, take their children to Fingles Pond amusement park- -a tacky place owned by corner-cutting Zak Oliphant and guarded by the dour Hump, as well as a hidden killer-dog illegally imported from the US. It's here that Jason, Sheralee's four-year-old son, has his hand bitten off by the dog--an attack that leads to legal trouble for Oliphant and some unanticipated outcomes for the Maggs family. While their luck changes in unlikely but fortuitous ways that include travel with trust-fund hippies, a parallel story concerns nice Jem and Gerry Hardy-Brown and their two children, all threatened by mixed-up adolescent Fergus. Former social worker Jem had once been in charge of Fergus, who fell in love with her (though he was only eight) and who continued to love her as he was moved from home to home because of increasingly disruptive behavior. But Jem hurt him badly, and now, out of prison, Fergus is determined to hurt her back. He stalks her, vandalizes her home, then steals the amusement park dogfor the killing he plans. But neither Jem nor Fergus is quite what they seem, and the end, though physically graphic, is psychologically even more horrible. An unlikely mix of humor and horror that, with the exception of the public-service-announcement messages, does manage to work- -but just.