This is book 13 of the "Travis McGee" series.

This note contains spoilers for the book.

Travis McGee #11. He chases the dead daughter of a crippled friend down into Mexico to try to find out what her last 6 months were like. They were nasty, she got involved with people exploiting the naive kids going down for cheap drugs, and using drugs to control people.

Actually, though, she's not dead. Should be upbeat, eh? Not especially.

This one has a major homosexual character and a major lesbian character. I don't think the portrayals are all that nasty; though they are among the bad guys mostly.