The Chessmen by Peter May
My rating: 4 of 5 stars
The final entry in the Lewis trilogy is less about the mystery and more about the history of Fin, Whistler and the band Amran (formerly Solas). This is May's MO for his books: wrap the present with a ton of backstory, which allows the reader to understand the present and lessens his need to really do a mystery story per se. That's not to say that learning about Fin isn't interesting, it's just that these are less mysteries than they are character studies.
And once again, the setting is critical. Lewis is almost as much of a character here as anyone, and at times I wonder if that's more May's interest than the people he's writing about.