This is number sixteen in Evanovich's number series that has Stephanie Plum as her primary character as a bounty hunter.
This time her boss and uncle the awful Vinnie has been kidnapped and is being held hostage for the payment of his debt(s), to the tune of 1.2 million dollars and the office core workers need to find him and the money. It is interesting but some of her earlier books were better, I think.