After several days of nonstop digging, the tunnel had now extended several hundred meters deep, slanting downward.
Because the tunnel was too deep and the air did not circulate, air turbines had been installed to blow fresh air into it.
Moreover, these villagers were not professional excavators, so mistakes were inevitable during the work. Fortunately, Ability Users were among them, so no major chaos arose. The tunnel was excavated both manually and mechanically, so even with nonprofessionals, the work progressed fairly well.
Chen Mo was also digging not far above their heads, always maintaining the same pace of advance.
Of course, as Chen Mo dug, he stored the rocks, soil, and so on in his Universe Bag, so there was no danger of being buried. During the nonstop excavation, he also used Talismans to reinforce the tunnel, eliminating any risk of collapse.
It was simply that the tunnel was too long, and the air circulation was poor. Staying inside for too long would cause difficulty breathing, and excessive carbon dioxide levels could even lead to suffocation. He did not have Rhine's methods, using mechanical turbines to exchange air with the Outside World. However, Chen Mo was a Foundation Establishment Realm expert, so he could simply hold his breath and use Internal Breathing. That way, he did not need to fear a lack of oxygen.
However, Internal Breathing could not last too long. Without oxygen for an extended period, he would still eventually suffocate. It was because his current strength was limited. If he reached the Nascent Soul Realm, suffocation would no longer be an issue. As long as he used Internal Breathing, he could sustain it for as long as he wished.
For now, Chen Mo could maintain Internal Breathing for several days without issue. After digging for a while,