The puzzle promised to give a coherent hint pointing to its solution while Tregarvon was thinking it out and fitting the pieces together; and so long as the mental effort continued to feed the fire of wakefulness he was all that an alert sentinel should be. But after the various suppositions had been properly labelled and docketed and pigeonholed the physical reaction came, and drowsiness sat upon his shoulders, riding him like an Old Man of the Sea. For a time he fought manfully, keeping up the struggle until he had exhausted every device he could think of and yielding only when he found himself actually falling asleep as he walked. The alternative to leaving the plant without a watchman was to call Carfax, and this he finally concluded to do. Groping his way blindly into the dark interior of the tool-shack, he stumbled over the spare coil of rope, sat down upon it for a momentary rest, and in the flitting of a bat’s wing was past help. When he opened his eyes again the high-riding moon had swung far into the west, the glade was bathed in a ghostly flood of gray shadow, and Carfax was shaking him gently. “Another act on,” whispered the impromptu call-boy; “no speaking parts out, as yet--only pantomime. But it is worth sitting up to see.” Tregarvon, still sodden with sleep, suffered Carfax to lead him to the outlook window. In the gray shadows he presently made out the figure of another intruder. Within the area of the sunken graves a man, old and black, if the uncertain light could be trusted, was squatting on the ground and rocking himself back and forth, his swaying body keeping time with the measure of a weird, crooning melody. From time to time, he would stop the swaying movement to take a small white object from a basket at his side. These objects he appeared to be arranging in some sort of a figure on the ground to the accompaniment of the droning incantation. “How long has he been there?” Tregarvon asked. “Just a little while,” was the low-toned reply. “I awoke about half an hour ago, and when I looked out, the moon was going over to the other edge of the world, and everything was quiet. A little later the basket man came; just appeared, you know, as if he had materialized out of the shadows. When I first noticed him he was doing his little song and dance, as you see him now.” “But what _is_ the ‘song and dance,’ as you call it?” “Write your guess on one side of a sheet of paper and send it to the puzzle editor,” chuckled Carfax, adding: “If we had begun doing that at first, the editor would have a choice collection by this time, don’t you think?” “I have been making a few more guesses,” Tregarvon offered. “I was coming in to unload them on you when my eyes went shut. What time is it?” “About two o’clock--the real witching hour. I want to go home.”