Rating: 4.125* of fiveThis is the third in what the publishers call The Shetland Islands Quartet in some places, A Shetland Islands Thriller in others. I hope that this betokens a realization on the part of Cleeves and her publishers that the series has the essential ingredient for longevity: Terrific characters entwined in believeable relationships.We see Jimmy Perez, our sleuth, living without gal-pal Fran Hunter while she's down south in London to visit family and friends. His every waking thought seems to return to her, to her daughter Cassie, and to the natural fears of a man in love whose lover is far away: Is she safe, is she having too good a time to want to come back, is this the end of my dream of happiness, all the stuff men think but never admit they're thinking.Sandy, Perez's Detective Sergeant, is also away, though closer to home...he's on Whalsay, a short ferry ride from Lerwick where Jimmy is based. While visiting home, Sandy's beloved grandmother is shot. It looks like a horrible, horrible accident. Sandy is first cop on the scene, naturally, and has to make hard calls about how to pursue the matter before Jimmy shows up to take over. Sandy's family will never be the same again, of course, but more importantly for the story, Sandy won't either. Jimmy helps Sandy grow into his manhood during this investigation, and this makes the book far richer than we'd have any right to expect from a simple thriller. When a second horrible death occurs, Sandy and Jimmy both conclude there are connections here that the two of them aren't making, and whether or not the deaths were intentional, the connections need to be investigated and explored. This takes each of them farther from his comfort zone than either expected.Cleeves's plot snake-twines around each character, squeezing the past and the present tightly together, and finally forcing the characters into one inevitable crushing future. It looks nothing like the present. It looks nothing like the future the characters saw coming. And that's why I recommend this book, and this series, with such a strong voice.