The Wind in the Box: The Unfinished Building at School

A horribly disfigured corpse was discovered in an unfinished building abandoned for years. The body was covered in wounds and kneeling on the ground, as if atoning for its sins...

After investigating, they found that a psychology lecture had been held in a classroom building a few hundred meters away at the time of the murder. Everyone who attended the lecture was a suspect.

But how could the killer have traveled those few hundred meters, committed the murder, and returned within ten minutes?

Theme: None.