In Class One B at Oak Tree School, a drawing lesson turns strange when colourful footprints appear on the blackboard and lead the children out of the classroom.
A new morning was settling over Oak Tree School, and Class One B was buzzing before the lesson had even begun. Mrs Ela stood by the big blackboard with a smile.
"Today," she said, lifting a box of chalk, "you will each draw your dream friend."
Pink chalk for Zosia. Green for Franek. Blue for Benio. One by one, the children stepped up to the board. Soon there were bright faces, round balloons, curly flowers, tiny stars, and a rocket with a long silver tail. The blackboard looked like a tiny burst of fireworks.
Then Kuba froze. Right in the middle of his rocket, something strange shone back at him. It was a little mark, bright and twisted, as if a piece of chalk had hopped across the board all by itself.
"Look," Kuba whispered. "That wasn't there before."
The whole class crowded closer. Across the blackboard ran a thin trail of colourful footprints, one after another, shining softly like wet paint. They slipped past the chalk drawings and disappeared under a desk near the door.
Zosia leaned in, her eyes wide. "Where does it go?"
Mrs Ela knelt beside the trail and touched her chin. "Only one way to find out. Stay together, and watch carefully."
Franek bent down first. The footprints led out into the corridor, where the air felt cooler and quieter than before. The children followed on tiptoe, past the classroom door, past the coat hooks, past the long row of windows.
At the end of the corridor stood a small door they had never noticed before. From behind it came a soft tapping sound.
Tap. Tap. Tap.
The colourful trail stopped right at the crack beneath the door, and Kuba held his breath as the handle began to move on its own.