"I expect it was done very much on purpose." The Doctor tucked his hands in the pockets of his long overcoat and sighed. "The chances of this happening naturally are astronomical. Plus, there's an element of planning in it. So many people have arrived here from separated realities, and so many of them have arrived here only to find that friends of theirs are here as well. Then there's that Welcome Center ... " He shook his head. "No. We aren't here by accident."