The Sign of Four

"Why was homicide called in for a missing persons case?" asked the sergeant.

Captain Doyle Lestrade examined the table, where a list of words written on a piece of paper sat next to a Scrabble board; all the tiles had been dumped back in the box except for six on a single rack, opposite an empty one. "Because," he said thoughtfully, "I don't believe Watson is merely missing."

"It looks like he is," muttered the sargeant.

"Yes, I suppose so," said Lestrade. "But why would he put away the board, but not the racks? Why leave this rack with 'XIIIII' in front of one chair? And why leave this list of words behind? It's clearly a challenge to us, either by Watson or...or by someone else entirely." He took out the board and started laying out tiles, moving them around as he went.

"What if the N in NODE goes over the E in WIFE, to form NE?" the sargeant suggested.

Lestrade shook his head. "I suspect these were the final words on the board--and all of them. NE is fine if it can be turned into another word later. ALONE, maybe? But...aha! I see now why 'The Sign of Four' was open on the desk over there. It wasn't just a hint as to the identity of Watson's opponent--"

"You still suspect his business rival, Arthur Holmes?"

"--but also as a clue to how the game was played: four tiles at a time! So NODE is played with the E under the W, and then not TAMED, but TAME is played, which also forms WET. Then the other person played DAZE..."

A few minutes later, Lestrade placed the last move on the board:

"You see, sergeant?"

"Um...no? All four corners are used--that's another four--but why HOBY? It doesn't mean anything to me..."
Lestrade chuckled. "It doesn't mean anything at all! You're letting yourself be misdirected. All the words have been played, and we know what Watson had left in his rack, but what of this empty rack over here? His opponent must have said he was out of tiles, but not all the tiles are in play. Until we reconstructed the game, we couldn't have known that the missing tiles spell...."

He opened his left hand and, one by one, laid out the remaining tiles: M-U-R-D-E-R.

"And there you are, sargeant: Arthur Holmes must have set these tiles aside beforehand, or over the course of the game; but either way, he was telling us exactly what he was up to." His expression became grim. "Arthur Holmes, in the library, with the Scrabble set. Sargeant, put out an arrest warrant for Holmes. And start looking for the body of Conan Watson."

Story by Tahnan