Even if Charlie told them he had the antidote that could free them from the Qing Eliminating Society's control… what then?

If they left with him, their families, whose whereabouts they wouldn't have known, would be massacred to the last.

With that deterring them, most of them were not about to escape by themselves.

Fleur's move was certainly savage—as if keeping the cavalry guard in line wasn't enough, she was taking preventive measures by threatening their families.

It was simply inhumane.