One winter morning in Seoul, Kyungha receives an urgent message from her friend Inseon to visit her at the hospital. Inseon has injured herself in an accident, and she begs Kyungha to return to Jeju Island, where she lives, to save her beloved pet—a white bird called Ama. A snowstorm hits the island when Kyungha arrives. She must reach Inseon’s house at all costs, but the icy wind and squalls slow her down as night begins to fall. She wonders if she will arrive in time to save the animal—or even survive the terrible cold that envelops her with every step. Lost in a world of snow, she doesn’t yet suspect the vertiginous plunge into darkness that awaits her at her friend’s house.