He writes figures in chalk on the floor around the circle, pausing to erase and replace one after a moment's consideration. They appear to be a blend of runes and mathematical symbols. It takes him a minute to pull out of whatever zone he's in mentally and answer the question.

"My last apprentice. From 1898 until 1907. But he's long gone." He frowns at nothing in particular, face downturned. "Stuart Prentiss. He was a good man. More of a philosopher than a fighter."