Blue Lightning by Ann Cleeves
Shetland Detective Jimmy Perez knows it will be a difficult homecoming when he returns to the Fair Isles to introduce his fiancee, Fran, to his parents. It's a community where everyone knows each other, and strangers, while welcomed, are still viewed with a degree of mistrust.
Challenging to live on at the best of times, with the autumn storms raging, the island feels cut off from the rest of the world. Trapped, tension is high and tempers become frayed.
Enough to drive someone to murder...
When a woman's body is discovered at the renowned Fair Isles bird observatory, with feathers threaded through her hair, the islanders react with fear and anger. With no support from the mainland and only Fran to help him - Jimmy has to investigate the old-fashioned way. He soon realizes that this is no crime of passion - but a murder of cold and calculated intention.
With no way off the island until the storms abate - Jimmy knows he has to work quickly. There's a killer on the island just waiting for the opportunity to strike again...