"Isn't it ordinary gravel?" Dudian's eyes lit up as he used the dagger to scratch the giant wall's surface as hard as he could. But he was able draw out sand and moss. Dudian suspected that these sand powder and moss were stained on the surface of the giant wall after a long time of accumulation.
Dudian didn't continue to study the giant wall after making two scratches. The current level of techonology would be able to identify the composition and infrastructre of the giant wall. He returned back to the exit of the passage and looked at Nicholas: "Don't waste time. Take them out!" (t/n: did the creators of the egyptian pyramids help to build the giant wall?)
Nicholas's face had turned ugly: "Master, are you planning to hunt this big guy which made those scratches?"
Dudian nodded: "Yes."