Marked by Irvine Welsh's scabrous humor and raw Scottish vernacular, Skagboys (W.W. Norton, $26.95) is the prequel to the best-selling phenomenon Trainspotting, an exhilarating and moving novel that shows how Welsh's colorful miscreants first went wrong. The novel transports us to 1980s Edinburgh, where the Trainspottingcrew is just getting started. Mark Renton has it all: the first in his family to attend university, he has a pretty girlfriend and a great social life. But when economic uncertainties and family problems intervene, Renton succumbs to the defeatism not to mention the drug use that has taken hold in Edinburgh 's tougher quarters. His friends are responding according to personality. Laid off, Spud Murphy is paralyzed in the face of long-term unemployment. Sick Boy, supreme manipulator of the opposite sex, is scamming and hustling for money and drugs. And meanwhile, psycho Franco Begbie is scaring the hell out of everyone. Darkly humorous, Skagboys gives a gritty and gripping portrait of a time, not unlike ours, when money was scarce, unemployment was high, and drugs seemed the answer.