Arriving in the area of Hakone, Senku, Taiju and Yuzuriha rush to make gunpowder. But a column of smoke suddenly rises in the distance, proof of the existence of other humans. Senku, conscious of the risks that this entails, decides to respond to these smoke signals.Tsukasa, who took Senku in hunting, gains ground, ready to do anything to prevent the production of powder. Our heroes then find themselves in a situation that seems to have no outcome.