The fully dimensional world of a long-running series is harder to find in a first mystery. There's nothing tentative, though, about Vincent H. O'Neil's debut novel, MURDER IN EXILE (Thomas Dunne Books/St. Martin's Minotaur, $22.95), which drops an engaging young sleuth into a sleepy little burg in the Florida Panhandle and hands him a tough case to cut his teeth on. Frank Cole landed in the coyly named town of Exile when his computer company up North went bankrupt and a nasty judge attached his future earnings. Frank is keeping his head down doing background checks for an insurance company when his investigation of a hit-and-run accident uncovers evidence of corporate corruption. Although you'd never guess it from the silly jacket art that makes his book look like an absurdist Carl Hiaasen knockoff, O'Neil is a polished storyteller with a breezy style and some interesting things to say about abandoned sons and their surrogate fathers.