Theo raised an eyebrow at the elves behaviour, slightly amused at the poor mannered creature. He found that it said something about the owner when an elf behaved badly, though of course he'd never say so out loud. Still, none of his own elves would ever dream of being anything but polite to guests in his house. They respected him far too much to shame him in such a way.
"Thank you," he said to the elf as they entered the room, just before it Disapparated. "Professor Dumbledore," he then said, turning his full attention towards the other wizard, following his example and nodding in greeting before taking the offered seat.
"I was hoping you'd help me with a bit of research I'm performing at the moment," he said, getting right to the point of the visit. "A few days ago, the Dark Lord contacted me and expressed interests in a certain symbol, used by Grindewald at one point. He asked, well demanded rather, that I'd find out its meaning and history. Naturally, I've discussed the matter with the Minister, and we decided it would be in our best interest to find out just what about this symbol that interests him so." That was a lot more honest than he usually was in these matters, but Professor Dumbledore was a man who it was best not to lie to, or even tell half truths to. That much he remembered from his school days, and he was not about to be so foolish as to try either when the truth worked just as well.
"The reason I am asking you is because wherever I turn in my research, your name seems to come up, especially in connection to Grindewald. I was hoping you'd be able to shed some light on the matter for me."
He pulled out a piece of parchment with the symbol and put it on the coffee table in front of Dumbledore. "I'm sure you know it already, and I'm hoping you'll know its history as well."