The Dead of Summer by Mari Jungstedt

The fifth in Mari Jungstedt's Gotland crime series finds Swedish sleuthing duo, Inspector Anders Knutas and reporter Johan Berg, investigating a campsite murder. When the body of local carpenter, Peter Bovide, is found floating a few yards offshore, Knutas cuts short a rare summer holiday to help his new second-in-command, Karin Jacobssen, comb the cow pastures for clues. As their leads dry up, and a second body is discovered, Berg and his young photographer, Pia, appear ahead of the game. This workmanlike mystery (deftly translated by Tiina Nunnally) is nicely helped along by unexpected developments in characters' love lives: the unfolding relationship between the Knutas and Karin, and Johan's faltering friendship with an ex-girlfriend.