Thorn is seeing a hippie, and is having a good time with that, but everything else in his life is going bad. His tied flies don't work, his friend stops talking to him, and so forth.
Meanwhile, said friend is working on a cruise ship, where he needs Thorn's help. Thorn eventually gets onboard, and we get a cruise ship mystery.
Not bad, but not as action packed as some of the other novels in the series, I think.