It's the dark nights in the run up to Christmas, and sailing sleuth Cass Lynch's first night on dry land is disturbed by strange noises outside her isolated cottage. Tiny footprints in the moonlit snow trail from her front door before mysteriously disappearing. Soon Cass learns others were visited by the same tiny feet in the night. It looks like ingenious local teenagers playing tricks - but what happens when festive games turn deadly? Cass soon finds out as a schoolboy disappears, leaving only a trail of footprints into the middle of a snowy field. She's determined to investigate, but uncovering the truth will also put her in danger.