This is book number three in Don Winslow's five-book "Neal Carey" series, originally published between 1991 and 1996. Like the first two I've read (here and here), I found Way Down on the High Lonely to be well-written and fun to read. Apparently out of print from the original publisher, but fortunately Kindlized.
As it opens, Neal's where he was left in the previous book: stuck as a prisoner in a remote Chinese monastery. Which would make for a pretty boring book. But never fear, Neal's "Dad" shows up to extricate him, and also to lead him on their next mission. (Which they perform for a secretive Rhode Island bank catering to the ultra-rich, such catering sometimes extending to extralegal investigations and operations.)
This time, their goal is to retrieve a missing child, snatched by the ne'er-do-well ex-husband of a Hollywood movie producer. He's absconded with the kid to middle-of-nowhere Nevada, which has its share of totally upstanding citizens, but also tin-hearted hookers and a secretive organization of nasty white supremacist religious kooks.
It's with that latter bunch where the kid was last seen, unfortunately. Neal goes undercover as a drifter trying to make sense of his life, ingratiating himself with the locals, both decent (including the local schoolmarm) and indecent. He's in a dangerously precarious position. It's a real page-turner (or, since I was on a Kindle, a next-page-button-pusher).