I recently read "Iron River" by T. Jefferson Parker. This is Parker's 17th book and I like him well enough to have read most (if not all) of them. However I have liked some of them more than others and this is one of the ones I didn't like so much.
The plot mostly concerns the efforts of a southern California ATFE agent, Charlie Hood, to stop the "iron river" of guns flowing south to Mexico. Hood and some of the other characters have appeared in at least one earlier book (although this book is largely independent). I don't think these books are Parker's best. Perhaps because they contain mystical elements and other unrealistic plot points. Or perhaps because they are more morally ambiguous than I generally prefer. Anyway this isn't a terrible book but there are authors I like better than Parker and books of his that I like better than this one.