Zosia liked the old mill by the river, grey and creaky. Every afternoon she sat on the platform with a small notebook. She counted the ducks, wrote down the tracks on the muddy bank. Figa, a mutt with black patches, was hanging around next to her. Fig sniffed between the planks and drank water from Zosia's hand. That day the river was quiet and the wind smelled of hay. Suddenly, something squeaked tinily in the reeds, like a whistle. Fig jumped up and set her ears. A magpie jumped out of the thicket with something silver in its beak. It perched on the railing and dropped the ring at Zosia's feet. It was a key ring with a tiny paw-shaped plate. The letter M and four dots were engraved on the metal. The magpie scrambled as if to say: follow me. Then she jumped towards the mill. Zosia put the pendant in her pocket and set off after the bird. The fig trotted tightly by her leg. There was a strange movement in the mill yard. Two neighbourhood cats were sitting on the fence. A hedgehog slid out of the grass like a little spiked ball. Red ears flashed in the shade of a poplar tree, then disappeared. The high-pitched screech sounded again, this time from inside the building. The door stood ajar and the threshold was marked with wet footprints. They were different: bird, cat and some unknown, wide ones. They arranged themselves in a line, like arrows to the circle itself. Zosia squeezed the strap of her torch and breathed deeply. "You stay with me, Figa," she whispered. She took two steps up and looked into the darkness between the beams. Something moved on the beam, like a shadow with feathers. She saw a flash of yellow eyes and a leather strap with the same paw. A screech cut the air so close that the boards trembled. And then from under the wheel she stepped out slowly....