The August sun shone through the dusty window in the attic of the old tenement, where Marianna had already spent the third hour digging through the family's junk. After moving to Lublin, her mother told her to "get used to the new place", so the girl decided to get to know every nook and cranny first. The tenement house on ul. Grodzka was a hundred years old - and exactly as many secrets as cracks on the walls. Suddenly, something under the old planking squeaked. Marianna crouched down and ran her finger over the crack. It seemed that the board was slightly raised, as if someone had carefully levered it with a knife. The girl looked around to see if anyone was watching her, although, after all, she was alone in the attic. She squatted down, slipped her fingers under the edge and - with slight difficulty - lifted the board. Underneath, she found a small canvas bag. It was not new, the material bore the obliterated initials: E.W. With trembling hands, she opened the bag. Inside, apart from a yellowish letter, lay an object resembling a key, but not that ordinary. Instead of the classic cut-out, it had something like a spinning crystal, which sparkled with the colours of the rainbow, sliding across Marianne's hand like a white-hot opal. The girl sat down on the floor, the letter held just to her face. It was written by someone with elegant, slanted handwriting. "If you are reading this, you really do exist. This key opens more than one door. Magic lives where you don't expect to meet it." Marianne felt her heart speed up - was it a joke? Or had someone left it specifically with someone like her in mind? With letter and key in hand, she looked at an old cupboard in the corner of the attic that she had not yet managed to open. It clearly bore a lock to which something so unusual could fit.... She squeezed the key in her hand once more. Holding her breath, she walked over to the wardrobe and slowly inserted the key into the lock. As she turned it, a quiet swish came from inside and the air around her began to vibrate, as if someone had just whispered to her through an invisible crack. The wardrobe door swung open of its own accord with a quiet creak, and for a split second Marianne saw not darkness, but moving, glittering lights and shadows, as if a completely different world awaited her on the other side....