Shaw and Innes are the lucky protectors of the remote Scottish island of Eynhallow. A mysterious, rocky outcrop uninhabited except for Shaw and Innes, it is steeped in paranormal legend. When a strange man arrives by boat a few days before Christmas, they're inclined to let him suffer the wounds he's endured lost at sea when they rescue him. After all, he spouts a lot of misconceptions about Eynhallow's most famous residents—the finfolk, a reputedly vicious strain of mermen of lore. When Peter Colcross realizes his saviors are themselves finfolk and can shapeshift into human form, he is forced to rethink everything he thought about sea magic and what might have become of his wife who disappeared after leaving their Glagow home in search of Eynhallow a few years ago. He's determined to find her because he's read that finfolk lure women to their doom on the island. But these mermen are kind and caring creatures. They're also gay. What is the mystery of Eynhallow, and will Peter ever discover the truth? And will he be able to forgive and let go of the past in order to move forward into the future?