This far north, they say the dead are with us... Hogmanay, the far north of Scotland. Alone on the shoreline, lobster fisherman Rob Sinclair pours a dram into the freezing waves of the North Sea. It's a family tradition; an offering to the sea spirit, the Selkie. That same night, a stranger arrives in Rob's village. A young woman, Mairi, charged by her dead mother to carry out three acts of vengeance. Bitter revenge for deeds done before Mairi was born. Lonely and damaged, Rob and Mairi are drawn to one another. Rob is beguiled by Mairi, but she is elusive, frustrating, her personality shapeshifting. The only certainty is that Mairi is not who she says she is...