Even though the series of Heavenly Abyss tasks had temporarily come to an end, and Dean McKenzie had received all the rewards due to him, he clearly knew that this matter was not yet fully resolved.
It had merely reached a temporary conclusion.
What was to come next, there would be follow-ups.
Dean had learned this from the group of people he had apprehended.
He did not eliminate the last group of people who trespassed into the Small World, he kept them.
Because Dean knew that keeping them alive was more beneficial than directly killing them to harvest their corpses.
By killing them, Dean would only gain their corpses. But by preserving them, apart from their corpses, he could also obtain information about the outside world.
Indeed, this turned out to be the case.