It was a Monday morning when Maks and Zosia walked into their 2B classroom. In the middle stood Mrs Kasia with a big smile on her face. Something, however, was different than usual. In the corner, right next to the blackboard, there was a mysterious cabinet. The cupboard was slightly larger than the others and had a shiny golden key attached on a string. Maks noticed it first and whispered to Zosia: - Do you see it? After all, it wasn't here yesterday! Zosia nodded and looked at the cupboard with her eyes wide open. - I wonder what's inside - she wondered aloud. Mrs Kasia winked at them: - 'This cupboard appeared today especially for our class. But beware: not everyone can open it. Only those who can solve riddles! The whole class squealed with joy. Max and Zosia immediately ran closer. The drawer was padlocked with a tiny keyhole. A note hung on the door: "Find the riddle and you will find out what the cupboard hides!". Everyone started looking around. Suddenly, Max noticed a folded note under the bench. With trembling hands, he opened it together with Zosia. On the piece of paper, a colourful riddle was written... But before they could read it, they heard a quiet whisper coming from the cupboard. Something was really there! Will Maks and Zosia dare to solve the riddle and open the mysterious cupboard? What will happen when they turn the key?