Spencer

House had been playing chess with someone in the teacher's lounge for about a week, but he didn't know who it was. He'd just walked in one day and one of the white pawns was moved, so he looked at it for a moment and then made a move from black. And the next time he returned, white had made another move.

It was actually quite a good game, and it made him look forward to going to the lounge, which was unusual. Also he was rather hoping he could find out who he was playing with.

And then one day he walked in just in time to see the new guy walking up to the board to examine it. "Aha!" he said. "Also, check."