"I doubt you would," Gellert said, locking his hands together behind his back, keeping the smile steady on his face. After all, from what he had gathered so far in his brief time here, most of the other inhabitants were from periods very far in his future--not to mention, most of them were English. That made it seem very likely to Gellert that the person behind this rather impressive bit of spellwork was from a similar period of time (likely slightly to the future of the furthest futuristic person present) and was native to or resided somewhere in Britain.
Why include Gellert, then? A German national who had attended school in Scandinavia, at Durmstrang, who had only set foot once in England and then only for a day and a half? Unless the mastermind was displacing people who were significant figures in history. Gellert's plans were hardly moderate, after all. And if everything went according to plan, he would soon be known as the man who had changed the face of wizarding civilisation forever. He bit back the twinge of self-satisfaction that accompanied this theory.
"My name is Gellert Grindelwald," he said. "It is a pleasure to meet you, Ms Potter."