This is the story of Mary. When she is still small, Mary meets Lanmo, a golden snake, who becomes her best friend. The snake visits Mary many times, he sees her city change, her family leave their home, he sees her grow up and he sees her fall in love. But Lanmo knows that the day will come when he can no longer visit Mary, when his destiny will break them apart, and he wonders whether having a friend can possibly be worth the pain of knowing you will lose them.