Feluś and Wanda build a wobbly sock castle in the playground. But when the towers start to tremble, they spot a pink tail poking out of the walls.
One bright morning, Feluś marched into the playground with a backpack that looked far too full for one small boy. Inside was a jumble of colourful socks his mum had meant to put away. He pulled them out one by one, grinning at the stripes, dots, and little hearts.
"Wanda!" he called to the squirrel, who was busy stuffing a peanut into the sand by the swing. "Want to build a sock castle?"
Wanda gave an excited twitch of her tail and bounced straight over. Soon the playground had a very odd castle on it, with sock towers, a rope bridge, and a cat-patterned flag hanging from the top. Feluś was just making a gate big enough for his toy car when the whole castle gave a tiny wobble.
Something rustled inside the checkered tower. Then, from a hole in the yellow sock wall, a pink tail slowly slid out. Feluś and Wanda froze. The castle shivered again.
"Did you see that?" whispered Wanda. "Who is in our castle?"