“I knew you’d throw some light on the thing! That makes it clear enough. But who’d have thought of a pun?”
“What do you mean?”
“Look here, Eileen. ‘Night unto night sheweth knowledge.’ That’s how it reads in English. These horse-headed pieces on the chess-board are knights—with a K. If the old Corinthian had put his text into English, it would have been fairly obvious: ‘Night unto night’ . . . and two knights on the board. So he used the Latin and concealed the thing. It could only be understood if one translated into English and took the sound of the words as a guide instead of the spelling.”
“I think I see. So that really means that one of these knights on the chess-board has something to tell the other one? What is it he can tell? You play chess; I don’t.”
Westenhanger shook his head.
“It’s not so easy as all that, Eileen. Chess doesn’t help much here, so far as I can see. But suppose we go up to the house and get a board and the pieces. It’ll be easier to see then, perhaps. If anyone comes across us, I’m teaching you chess, remember. We don’t want this talked about.”
“Very good.” She rose to her feet. “Let’s go now.”
They went up to the house and Westenhanger unearthed a chess-board and men in the library. Soon he had set up a duplicate of the diagram with the pieces, and he and Eileen bent their heads over it.
“Even if you don’t know chess, at least you know what a knight’s move is: two squares on and then one to the right or left. You can make the move in any direction you please. Like this, or this.”
He illustrated it on the board.