Four to Score (A Stephanie Plum Mystery)
Janet Evanovich
Pretty succinct (albeit complicated) description from the publisher:
Working for her bail bondsman cousin Vinnie, Stephanie Plum is hot on the trail of revenge-seeking waitress Maxine Nowicki, whose crimes include bail jumping, theft, and extortion. Someone is terrifying Maxine's friends, and those who have seen her are turning up dead. Also on the hunt for Maxine is Joyce Barnhardt, Stephanie's archenemy and rival bounty hunter. Stephanie's attitude never wavers - even when aided by crazy Grandma Mazur, ex-hooker and wannabe bounty hunter Lula, and transvestite rock musician Sally Sweet - and even when Stephanie makes an enemy whose deadly tactics escalate from threatening messages to firebombs.
The story itself is actually more complicated. But funny AND a lot of fun. Not much socially redeeming value, maybe, but a good read.