The Big Kahuna / Janet Evanovich and Peter Evanovich.

Straight arrow FBI Agent Kate O'Hare always plays by the rules. Charming con man Nicholas Fox makes them up as he goes along. They're working together to tackle the out-of-bounds cases ordinary FBI agents can't touch. And their relationship? Well, there hasn't been so much explosive chemistry since Nitro was introduced to Glycerin. Next on the docket: the mysterious disappearance of the Silicon Valley billionaire known as the Big Kahuna. No one seems keen on helping. His Instagram model wife and shady Czech business partner are more interested in gaining control of his company, and for that they need a dead body... not a living Kahuna. The only lead is the Kahuna's drop-out son, who's living the dream in Hawaii. To get close to him, Kate and Nick go undercover as a married couple in the bohemian, surfer community of Paia, Maui. Living a laidback lifestyle isn't exactly in Kate's nature, but the only thing more horrifying is setting up house with Nick Fox, even if he does look pretty good on a longboard...