Mysterious Footsteps in the Night

In the dark of night, Zhang Yi heard footsteps moving around in his room. He turned on the light, searched the room thoroughly, and found that there was no one else there except for himself.

But the footsteps continued, as if they were coming from downstairs and also as if they were coming from within his own home.

He thought for a moment, then decided to lie down on the floor, pressing his ear against the floor to listen carefully.

This time, he heard it clearly. The footsteps were indeed coming from downstairs, just beneath a floorboard.