Eve closed her chemistry notebook and looked around the empty classroom. The sun was slowly hiding behind the horizon, and the last rays of light were coming into the room through the dirty windows. In an hour, the school was going to be completely closed. The teacher, Mrs Karpowicz, allowed them to stay longer because they needed to finish their presentation for the competition. Apart from Eve, there were also Kuba, Agata and Filip. They were all sitting around a table, bent over a laptop. - 'Oi, anyone know where the socket is? - asked Agata, shifting the powerbank from hand to hand. - Over there, behind the wardrobe,' chuckled Filip without lifting his head. - I think. At the same moment, Kuba lifted his gaze from his phone and looked at the board on the wall. He tried to focus, but the atmosphere of the empty school had something unsettling about it. As Eve moved the wardrobe away, she noticed a small flap in the floor - most likely a hatch to some storage room. - Look at this! - she called out quietly, pointing to the flap. Philip went up first. They tried to pry it open with a ruler and then with Eve's penknife. After a moment, the flap swung open, revealing a winding staircase leading into darkness. - What is...? - whispered Kuba. - I think it's... not on any school plan. For a moment no one spoke. Everyone stared at the stairs, from which a slightly cool breeze was blowing. Eve felt her heart beating faster. They decided to go down; curiosity was stronger than fear. Once they were downstairs, their phones lit up the narrow brick corridor. After a few steps, they heard a deafening rustle, and just ahead of them, a strange shadow appeared on the wall - it moved slowly, as if something was hiding just around the corner....