Senku does not trust the motivation of Shishio, so he will try to hide his plans from a new and unforeseen enemy for his plan to revive civilization.

Senku has the idea of ​​creating gunpowder to have a way to balance the scale and have a chance to defeat Shishio. The production of gunpowder causes a fire. Shortly thereafter, Senku and the others discover smoke signals on the horizon. An accident? Hardly likely. Apparently there are other people in the stone world ...

Shishio is determined to end Senku's life if he does not promise at that moment that he will abandon his idea of ​​recovering civilization as it was before the incident.