This is number 11 in Randy Wayne White's series of novels about Marion "Doc" Ford, a marine biologist living in southwestern Florida, with a darker, violent, past doing shady things for Your Federal Government. Nowadays, though, he's content to run his biological supply business, do a little research on spawning tarpon in captivity, and hang out with his colorful friends.
But that wouldn't make much of a book. Doc has—or so he thinks—a bastard son, Laken, living in the fictional Central American country of Masagua. Doc is still somewhat captivated by the boy's mother, Pilar, who was once married to an now-exiled Masaguan general. The boy becomes a pawn when he's kidnapped by Praxcedes Lourdes as part of a plot to bring the general back into power. But Lourdes is a terribly disfigured psychotic freak, whose highest joy is in setting people on fire. And he has his own plan in mind, almost immediately double-crossing the general.
The kidnapping brings Pilar back into Doc's life, much complicating his relationships with ex-lesbian Dewey Nye and his drug-soaked buddy Tomlinson. The general and his thugs are also in the picture, trying to recover their shattered plans. But Doc's overriding purpose, of course, is to discover the whereabouts of his son, and to thwart Lourdes' gruesome scheme. As it turns out, Laken is not content to be a passive victim, and he manages to drop ingenious clues to Ford. It all leads up to an exciting climax at sea.