An Unexpected Turn of Events

"MOVE! MOVE!"

It was impossible for a simple drill bit to drill through a 400-meter-thick granite layer, but the "Digging Warrior" that landed here was not the same as the one that landed on the surface of Mars. In order to adapt to the complicated battlefield environment of Mars, the Digging Warrior had gone through countless modifications in the hands of the colony engineers to clear out Devil Worm nests located deep inside the ground.

A thumb-thick groove pattern was added to the side of the original drill bit, which was connected to a corrosion-resistant material container filled with organic solution.

And the solution was Devil Acid!

The corrosion-resistant cobalt drill bit rotated at a high speed, spewed out Devil Acid, and seeped into the granite formation below. The granite and the steel protective belt were both easily penetrated by the drill under the corrosion of acid.

The speed of the downward advancement surprised everyone!