On Christmas Eve, Kuba was cutting ravioli and Grandma was sticking dumplings. The flat smelt of poppy seed and dried fruit, and the snow was falling outside the window. An old cuckoo clock, inherited from his great-grandfather, ticked above the sideboard. Every hour, a bird shot out and gave a slight nod. Kuba took pictures of the Christmas tree and counted the baubles so that none would disappear. When they had finished the last dumplings, the clock suddenly struck thirteen times. Something clattered inside, as if a coin had fallen on the boards. Kuba looked under the pendulum and pulled out a small metal key. It had a snowflake on its head and was warm in his hand. Grandma touched it carefully and squinted her eyes for a moment. She said it had belonged to her great-grandfather and had been lost years ago. Then the sound of a bell, not from the Christmas tree, came to them from the cage. The lights in the living room flickered slightly, as if in a quiet thunderstorm. Grandma took the torch and Kuba put on a jumper and boots. They went downstairs, where the stairs creaked and the air smelt of apples. The cellar was cool and dark, with the shadow of bicycles against the wall. Their wooden cell had a padlock with a snowflake sign. The key fitted as if it had been waiting here all winter. Before they could turn the lock, they heard a soft rustling inside. Kuba looked at his grandmother; she was nodding, although she was pale. He turned the key and the metal clicked and the door swung a finger wide. Warmth gushed through the crack, as if from an oven, and the smell of cinnamon. In the semi-darkness a glow shimmered, green as an aurora above the snow. The bell sounded three times, and someone whispered Kuba's name.