U is for Undertow, by Sue Grafton.
Sue Grafton started her "alphabet" mystery series with A is for Alibi back in the '80s and hasn't looked back since. Her novels, featuring P.I. Kinsey Millhone, still take place in the late '80s, this one in 1988, where Millhone can frequently be found typing away on a Smith-Corona typewriter.
This book, as in all her alphabet mysteries, was good, but the ending was just a little too 'pat' for me, though admittedly Grafton did take a long time connecting all the storylines running through the novel.
3 out of 5 stars.