Diesel is the third hunky male in bounty hunter Stephanie Plum's complicated masculine menagerie. Her number one interest --- Trenton, New Jersey cop Joe Morelli --- is away, working undercover while Stephanie dog-sits Bob, his galumphing retriever. Number two is the dangerous Ranger, who occasionally helps Stephanie chase down the hardcore bail-jumpers and performs other undefined activities, some of which drive Morelli crazy. 

Diesel, the testosterone-charged hunk who first popped up (quite literally) in the Christmastime novella VISIONS OF SUGAR PLUMS, boasts other-worldly skills, among them an apparent ability to walk through walls. He suddenly appears out of thin air in Stephanie's kitchen with an offer she can't refuse. Annie Hart, wanted for armed robbery and assault with a deadly weapon, has vanished. She is the only big-ticket bond-skipping capture between Stephanie and her next rent payment. Diesel tells Stephanie that he has Annie under wraps to protect her from someone who is out to get her for messing up his marriage.

Annie, a relationship expert, needs to stay hidden until Diesel can defuse her angry client who belongs to the same mysterious class of near-humans as Diesel. Unlike Diesel, who performs good deeds, this man's specialty skill can seriously incapacitate Annie or anyone who comes into contact with him. Annie will cooperate with the law when Diesel takes care of the bad guy, but will stay hidden only if he will fulfill the romantic wishes of a backlog of her lovelorn clients in time for Valentine's Day, just days away. Diesel, short on personal relationship skills, enlists Stephanie to help him clear Annie's case log. 

Stephanie is hardly an expert on interpersonal relationships herself, especially with the opposite sex, but Diesel needs help and Stephanie needs the money. They embark on a mission to fix up the five unlikely candidates for romance in time for a happy Valentine's Day for all. Among the lovelorn are a shy butcher, a pudgy veterinarian, an overworked mother of three, a past-her-shelf-date virgin and even Stephanie's very pregnant sister's commitment-shy fiancé. Throw in sidekick Lula and Ranger's bodyguard Tank, and you have a New Jersey lovefest. This leads to a comical exercise in mis-matchmaking and a dicey chase through Trenton's streets, involving Stephanie's family and friends.

Only Stephanie Plum could find herself combining bounty hunting with matchmaking. She hones a whole new skillset for her resume in this short, funny, very Evanovich confection just in time for Valentine's Day.