They stooped over it and examined the fibre.

“Ordinary sewing-silk off a reel, obviously,” was all that Sir Clinton vouchsafed.

Wendover thought he had seen more in the matter.

“Don’t you see what it is, Clinton? Ariadne’s clue! It’s a thread that the murderer must have been using to find his way out of the Maze in a hurry.”

“I showed you before that there’s no difficulty in the Maze if you’ve once been taken to the centre.”

Wendover had his answer in readiness.

“Yes. But suppose you were the murderer, you would have to get out in a hurry, wouldn’t you? And you might lose your head. Anybody might get confused in the flurry. So he took the precaution of laying the thread to the exit; and all he had to do was to follow it and reel it up as he went. And this time a bit of it caught somewhere—see, this end’s tangled in the hedge—and so broke off and he had to leave it behind. When the Shandons were murdered he probably managed to reel up the whole of it and so left no trace behind him.”

“Sounds plausible,” Sir Clinton commented curtly. “We may as well collect the specimen, though really there’s nothing distinctive about it. One bit of thread’s very much like another.”

“Sherlock Holmes might have made more out of it than that,” said Wendover, rather resentful at the way his discovery had been treated.

“Doubtless. But as he isn’t here, what can we do? Just bumble along to the best of our poor abilities. That’s what I’m doing, Squire.”