"Oh, well, perhaps he tripped and fell, striking his head as he went down. Then again, a rotten plank might have given way under him, and let him get an ugly fall," Matty replied.

"That sounds reasonable enough," said Elmer, "and now I want some of you to scatter around and see if you can discover any trace of our missing comrade. Red, you get a long pole and poke down in that deep pool, though I feel pretty sure you won't find any sign of him there, because there isn't a mark of blood on the rocks, as there would be if he had fallen from up here on the dam."

The boys looked aghast.

Up to this point perhaps Landy and several others may have indulged in a hope that after all perhaps this might only be a little finish to the remarkable game of fox and hounds which they had been playing.

Indeed, Red and Larry had once or twice even exchanged sly winks. They actually suspected that Elmer had secretly ordered Nat to conceal himself, up among the branches of a tree, perhaps, so as to have the whole party guessing, and running around like a pack of dogs off the scent.

Now the last vague hope in this particular seemed shattered by Elmer's thrilling suggestion.

And more than Red's horrified eyes roved in the direction of the ugly black pool, across the surface of which the foamy white bubbles kept circling constantly, as the surplus water ran over the dam.

"Where will the rest of us look, Elmer?" asked Matty, breaking the awful silence that had gripped them after hearing the scout master's suggestion.

"Any old place," replied Elmer; "only I guess you needn't go far along that farther sh.o.r.e, because Toby and Ty were there where you see that big oak tree."

"They couldn't see the dam from there, could they?" asked Red, quickly.

"No, that's true," answered Toby.

"And so they wouldn't know whether anybody knocked poor Nat over here; or if he went across to the old mill," Red continued.

"Right you are, Red," replied Ty; "but neither did we hear any shout. An old bluejay was screechin' in the woods near us. Yep, a feller might 'a'

called out and we not noticed it."

"I want two of you to go with me to the mill," said Elmer.

"Count me for one!" cried some one, instantly; and of course that was the eager Chatz, who would have started a new rebellion had he been debarred that privilege.

"And I'm the second victim," declared Lil Artha, with a grin, but at the same time looking very determined.

"All right," said Elmer; "fall in behind me, and we'll see what the inside of the mill looks like."

CHAPTER IV.

THE SEARCH FOR A CLEW.

Following the lead of Elmer, the tall lanky scout and the wiry Southern boy quickly found themselves at the other end of the mill dam.

Lil Artha had cast his eyes about him as he cautiously made his way along. He seemed to be figuring on what chance there might be for an active chap like Nat Scott slipping on one of the wet and moss-covered stones, to go tumbling down toward that suspicious black pool.

Not so Chatz Maxfield.

Apparently he had made up his mind from the start that this strange vanishing of their comrade must have some connection with the mystery of the old mill.

Did they not admit that three separate times people had tried to live there in the dwelling that was part and parcel of the mill; and on every occasion they had given it up as a bad job?

Why?

Well, it seemed to be understood that none of them could stand the sights and sounds which had come to them while under that roof.

People might scoff at such things all they had a mind to, but surely it seemed as if there must be _something_ in it.

At any rate, everyone of those three families believed the mill house haunted. And for many years now, no one had had the nerve to occupy the place.

And yet it had once been a paying venture, for the main road was only a few hundred yards away from this lonely, forbidding-looking pond, where the frogs grew so large and the red-marked "turkles," as Ty Collins called them, were so saucy.

"Careful here!" warned Elmer, as they arrived at the runway, where in times past the water was turned on when the mill was to be operated.

The boards were rotting and slimy, and if one made a slip he might get a wet jacket in the sluice, where there was more or less running water.

Elmer held up a hand to hold his comrades back. He seemed to be down on his hands and knees, as though examining something that had just caught his attention.

"What is it?" asked Lil Artha.

"He came this way, all right, boys."

"Do you mean Nat?" questioned Chatz.

"Why, of course," replied the leader.

"How do you know?" continued Chatz.

"I've been following Nat's trail for miles," answered Elmer, "and sure I ought to know what his footprint looks like. Here it is on this clay just beside the sluice. Wait till I cross and see if he made the other side all right."

"He must, because he ain't in the sluiceway," remarked the tall boy.

A minute later and Elmer, who had carefully crossed over, testing each board before trusting his weight on it, called out:

"The marks are here, all right, fellows. Nat did start to look into the old mill. Come over, but be careful. Go slow, Chatz," he warned again, as the impetuous Southern boy slipped, and might have landed in the slimy sluice only that Lil Artha threw out a hand and clutched him.

They were now almost in the shadow of the deserted mill. It looked gloomy and forbidding to the eyes of at least Elmer and the tall lad, though Chatz may have considered it an object well worth coming a long distance to see.

"Wow! I must get some pictures of this same old ruin while we're up here," said Lil Artha, who carried a little pocket camera along, and was a very clever artist indeed.

"A fine idea," remarked Elmer; "but there are a lot of good people in Hickory Ridge who would think a picture of Munsey's mill very tame and incomplete without the ghost showing in it."

"Ah!" said Chatz, his face aglow.

"Oh, well," Lil Artha went on, "perhaps now I might be lucky enough to tempt that same ghost to pose for me. Anyhow I mean to ask him, if so be we happen to run across his trail."

He looked at Chatz, and then winked one eye humorously at Elmer. But the Southern boy did not deign to take any notice.