In the depths of the Nordic winter, the beautiful Island of Aero is steeped in pre-Christmas cheer and Danish hygge. But in one dark and forbidding attic, a gruesome secret waits to be discovered.
Two Italian sexagenarians and a stubborn, loveable Basset Hound are travelling across the sea to the historic town of Ærøskøbing. The ever-positive Dora is clasping her hands in delight at the prospect of their latest homeswap; her more feisty friend Etta is picking a fight with an equally belligerent Danish woman; and Leon? Well, Leon is saving a small child from certain death. Just another day in the life of a brave and noble dog.
Little do the three travellers know just how significant the people they meet during the ferry crossing are going to become over the next couple of weeks. As Aero rises before them from the Baltic Sea, an unsolved murder, a mythical treasure, an unrequited love and a bitter family feud await them. Can the analytical Etta, empathetic Dora and sharp-nosed Leon finally lay the dead to rest and lead the living to the happiest of Christmases? And who is destined to receive the most precious gift of all?