In an isolated lighthouse live two sisters, Anna and Polina, and their mother, Vla. Polina gets engaged and leaves the lighthouse, only to go missing at sea. Concerned for her well-being, Anna and her mother go searching for her, on the desolate and lonely sea.
Anna and her mother do not see the world the same way. What Anna can't find in her mother, she looks for in her grandmother, Yona. Yona died at sea and appears to Anna as a ghost. She guides Anna in her quest to find Polina, but does not appear to her daughter, Vla.