[ Zara's surprise gets Ciel's mouth to set in a thin line, and the bitterness is unmistakeable on his face. He's surprised that anyone would trust their captors (as he thought of them, at least) so willingly, so seeing anyone naively trusting that this was anything but the work of some other power. However, in reality, Zara is the reasonable one here and Ciel is just extremely paranoid. ]

Why not? They can bring us here, apparently, and they can clearly manipulate other things. It doesn't seem unreasonable that they could do this too.