The first storm of September was brewing in earnest when Michal, Lena and Igor returned to the biology room to collect their forgotten notebooks. The school looked completely different in the evening - the corridors were empty and quiet, the lights shone less brightly, as if saving energy for the next day. With every passing moment, the world outside the windows was sinking more and more into darkness. - Have you ever seen the school after hours? - whispered Igor as they approached the door of room 211 - It is said that everything here lives its own life then. Michal snorted with laughter, but Lena looked at him thoughtfully. - 'My older sister says there's an old shelter from the war under this hall. However, no one has ever been there. As Lena turned the key in the lock, they heard the floor slam quietly. They looked into each other's eyes in surprise, because the sound was different from usual - as if a muffled whisper was coming from under the floorboards. Igor looked around in the semi-darkness and suddenly noticed a circle scratched on the floor on the old tiles. He gently moved his foot and then the tiles squeaked and... gave way under the pressure. A small flap appeared in front of them. - All right... - Michal swallowed his saliva. - Shall we open it? The school at that moment seemed like a completely different place to them. A cool breeze and the smell of dust came through the ajar hatch. Lena took out her phone and illuminated the interior. In the gloom, they could see a staircase leading down into the depths, where some shapes could be seen. - It looks like... a real secret passage. - whispered Lena with growing excitement. Igor was the first to slip his head inside, followed by Michal and Lena. As they went downstairs, they heard a loud bang. A flap slammed over their heads and the light from the phone revealed the outlines of old-fashioned benches and dust-covered blackboards before them. However, at the end of the subterranean classroom something moved....