Moist

 Moist by Mark Haskell Smith 320 pp.

If you're a fan of dark humor, this is the book for you. Bob has a cushy job at a pathology lab where he spends most of his time playing Tetris and surfing the internet. His girlfriend is a sex therapist and it sounds like a perfect life. When the lab receives a heavily tattooed severed arm Bob becomes obsessed with the image of a buxom women performing a sex act. While delivering the arm to the crime lab, Bob is kidnapped by Mexican mobsters who don't want the police to identify the arm as belonging to one of their own. Soon Bob is going by Roberto and wanting to be part of the Mexican mob, especially after they promise to introduce him to the woman in the tattoo. Esteban, the mob boss, decides he likes Bob and wants to keep him around, others in the gang want him gone, permanently and are plotting to eliminate him. Meanwhile, a wine snob police detective desperately wants the arm found in hopes of bringing down the mob. In the course of his investigations he hooks up with Bob's ex-girlfriend who has a disturbing sexual reaction to guns. The mobsters decide to throw the cops off their trail with a substitute arm from an unwilling victim that they then have tattooed to look like the original arm. It's all pretty farfetched and hilariously grotesque.