"Tap... tap... tap..."
In the dark and confined hallway, Yun You and the group of three wore heavy, fully-sealed hazmat suits, stepping over the hard rock steps and exploring the tunnels.
Initially, when they first entered the mine, Jack cautiously walked back and forth to see if normal entry and exit through the mine passage was possible.
At first, everything seemed safe; he could leave the pit freely and also communicate with the outside mine supervisor.
But as the trio continued deeper into the tunnel and passed the first corner, everything changed.
Almost in an instant, the light from the outside vanished completely.
When Jack turned his head around, the exit on the other side of the corner had transformed into a completely unfamiliar tunnel, pitch black, leading nowhere known.
Clearly, at the moment the trio stepped into the corner, the space within the tunnel underwent a significant change.
