On the way to escort Gilder and his group of refugees, who were trapped by the demon of fear, back to the city, they once passed by an abandoned human town.
Time had granted them the ability to repair that human town, but the precondition was that they needed to find... or rather build the things necessary to activate the city's functional buildings.
Then came the issue of population.
No matter how many and how good the buildings were, there needed to be people to use them. The former residents of Black Street clearly weren't suitable for direct relocation. Asking them to abandon the safety and warmth of the city's periphery for a completely new and strange wilderness was something normal people would probably not accept, and the city wouldn't sit idly by as so many people abruptly left.
But now... these refugees, abandoned by the city, were exactly in a situation of having nowhere to go.