There's really a bomb

Knowing that the Experimentals were capable of using simple explosives, it was extremely frightening to find a bomb in the tunnel.

During this period, the Zhou Consortium had deployed special instruments to check on the decibel levels in the vicinity of the stronghold walls, because they were afraid they could not detect the sound of the Experimentals digging tunnels underneath the stronghold.

But looking at this underground tunnel in front of them, the Experimentals must have dug it a long time ago. How else could they have avoided detection by the Zhou Consortium troops?

The soldier who discovered the bomb was panicking as he tried to run back frantically. But before he could get out of the pit, the bomb behind him suddenly exploded.

The ground around the stronghold walls looked like it had suddenly been plowed as large clods of earth started breaking apart. Like the water surface, a dirt "wave" swept across the ground.