For an experienced chess player like Theo Theodorakis, it's quite easy to recognize someone's distinctive style of play once you've played them a couple of times. The problem is that he doesn't know the identity of the opponent he faced in the Westing mansion, who opened up the game by moving a white pawn. Theo responded by defending with a black knight.

On a very basic level, Theo is always asking people if they play chess because he loves the game and is always looking for an opponent. But there's a much more serious reason behind his constant questioning. Theo figures that if he can find out which of the heirs plays chess, then he'll be able to uncover the identity of his opponent. In turn, that could well lead to the exposure of the murderer in their midst.

Doug's not convinced. “Since when is chess-playing evidence for murder?” he asks. But Theo knows that since they don't have a whole lot of information to go on, it might be worth a try to find out which of the heirs, besides himself, is a chess-player.

When it comes to playing The Westing Game, no two sets of clues will be alike. But if Theo can at least make a start, then perhaps it will be possible to gather all of the available clues together in one place and make a single message. That way, perhaps the identity of the murderer will finally be revealed.