The corridors of the college were deserted as Adam left his evening lecture. The last lights flickered mischievously and the echo of his footsteps echoed off the high walls. He walked slowly, with his thoughts running away from the next exam he had in just two days. He passed room 213 - as he had done for the past three years - but this time something stopped him. On the blackboard, among the scribbled remnants of mathematical formulas, was a fresh sign: "Don't open the door after midnight. Never." Adam looked at the inscription for a long moment. It was no joke - the letters were cursive, as if written in haste, and someone had left a key next to them, tied with red thread. The boy peeked through the glass of the door, but darkness reigned inside. At the same moment, he was joined by two friends from the student club - Magda and Olek. They noticed the strange scene and quickly approached the door. - What happened? - Magda asked quietly, feeling the atmosphere of tension. Adam showed them the sign. - Maybe someone is playing a prank? - said Olek, but uncertainty could be heard in his voice. At the end of the corridor there was a quiet clatter. The three young people looked at each other, holding their breath. - 'Let's try opening this door... maybe we'll find out what's going on,' Magda suggested in a whisper. Adam lifted the key, and the darkness behind the door seemed to thicken. Everyone paused in suspense as Adam slid the key into the lock and.... (the continuation depends on your imagination).