Before turning in, Grace made a circuit of the camp and the bushes and the trees surrounding it, halting where the ponies were tethered to see that they were properly tied for the night. Soon after making camp she had taken possession of Washington's harmonica, for it was all-important that attention be not attracted to their camp that night.

Grace was certain that they had not yet heard the last of their mountain enemies and that trouble might be looked for from that direction, hence no precaution must be overlooked with regard to protecting themselves.

"Tom was right," murmured Grace, when, after giving Washington and Hippy final directions, she had retired to her tent and lain down with rifle and revolver within easy reach.

Lieutenant Wingate put out the fire and sat down to watch, rifle in hand. Grace got up an hour later and, peering from her tent, saw Hippy sitting with his back against a rock. At first she thought he was asleep; then, when she saw him take off his hat and smooth back his hair, she knew that she was mistaken.

It was long past midnight when Grace again roused herself and got up with a feeling that all was not well. A quick survey of the camp from her tent revealed nothing disturbing. Hippy was in the same position in which she had seen him some hours before and not a sound was heard from the ponies' direction.

Picking up her rifle, and strapping on her revolver, Grace stepped over to Hippy and peered down into his face. He was sound asleep and snoring.

"It were a pity to wake him," she muttered, moving quietly away and sitting down within a dozen feet of the sleeping man to guard the camp for the rest of the night.

Grace suddenly tensed with every faculty on the alert. She thought she heard something moving cautiously in the bushes at the left of the camp.

A few moments of listening convinced her that she was right. She knew that none of her outfit was out there and that Washington Washington was sleeping in his little pup-tent a few yards from her, for she could hear him breathing.

The Overland girl used her eyes and ears, and a few moments later she made out a vague form at the edge of the camp. Even then she would not have seen it, had it not moved to one side. The dark background prevented her being able to make anything out of the form, except that it was a human being.

Having satisfied herself of this, Grace raised her rifle, aiming it above the head of the intruder, and waited. Herself being in a deeper shadow, her movements were not observed by the prowler.

Grace put a gentle pressure on the trigger. A flash of fire and a deafening report followed.

Hippy Wingate sprang to his feet.

"Wha--wha--wha?" he gasped.

"Don't get excited," soothed the calm voice of Grace Harlowe. "I shot over the head of a prowler. Go back to your tent, Washington," she directed, as the colored boy ran out ready to bolt into the bushes.

Grace had heard the prowler crash through the bushes in his haste to get away, and felt reasonably certain that they would not be troubled by him again that night. In the meantime the others of her party had sprung from their tents, excitedly demanding to know what had occurred. She told them briefly, and advised that they go back to sleep.

"You too turn in, Hippy," directed Grace. "It is too bad to have spoiled that lovely sleep. I will look after the camp for the rest of the night."

Without a word Lieutenant Wingate went to his tent. He was ashamed of himself despite his former a.s.sertion that Nora Wingate always provided this emotion for him.

"I think I'll ask Emma to sit up and 'con-centrate' to keep me awake after this," muttered Hippy, and then lost himself in slumber.

The camp once more settled down and was not again disturbed, but Grace kept her vigil ceaselessly through the rest of the night. The girls did not know the details of the disturbance until breakfast next morning when Grace told them all she knew about the occurrence. After breakfast she and Hippy searched the ground about the camp and found traces of their visitor. In leaving he had made no effort to hide his trail, probably having been in too great a hurry, but Grace did not consider it worth while to try to follow the trail.

"We must make time, you know," she told her companions upon returning to camp. "If we are late in keeping our appointment with Tom, he will be worrying for fear something has happened to us."

"Something probably will have happened to us by that time," observed Elfreda solemnly. "Several somethings, perhaps."

After considerable milling about, after retracing their steps along the mountain rivulet, they found the trail that they were in search of, the footpath that led in the direction that they wished to go. On either side of the path was a jungle-like tangle of shrub and vine, through which the party, riding in single file, were obliged to force their way.

So dense was the foliage that they could not see each other, but they kept up a rattling fire of conversation back and forth, much of which was directed at Hippy who was leading and doing his best to beat down a path for those who were following.

This continued for some time, until finally Hippy's mount seemed to be getting lazy, for Elfreda, who was riding directly behind the leader, b.u.mped into his pony several times.

"Come, come, Hippy! Have you gone to sleep?" demanded Elfreda. "We shall never get out of the tangle at this rate."

There was no reply, and when Elfreda communicated her belief to her companions that Hippy had gone to sleep on his saddle, there was much laughter. Emma called out that, so long as the horse kept awake, they would be all right.

This condition of affairs continued for some little time, until finally Elfreda rode out into a rugged, rocky clearing and made a discovery that, for the moment, left her speechless.

Hippy Wingate's pony was browsing at tender blades of gra.s.s that were sprouting from crevices in the rocks, but its saddle was empty.

"Hippy! Oh, Hippy!" called Miss Briggs.

There was no response to her call. The pony raised its head and looked at her and then resumed its eating.

"Grace!" cried Elfreda in a tone that thrilled every member of the party. "Hurry! Hippy has gone!"

CHAPTER VII

A VOICE FROM THE SHADOWS

The Overlanders came trotting into the clearing, Grace bringing up the rear of the line just ahead of Washington and his mules, who still were some little distance behind.

"What is it?" called Grace as she burst into the clearing.

Miss Briggs pointed to Hippy's empty saddle, and it was not until then that Nora Wingate fully realized the meaning of the scene.

"Hippy, my darlin', where are you?" she cried excitedly.

"Steady now," cautioned Grace. "It will profit us not at all to lose our heads. Spread out and search the clearing. First, tie your ponies so they don't disappear and leave us in the lurch."

The girls quickly slipped from their saddles and began searching, Grace first having examined the saddle of Hippy's pony. She found his rifle in the saddle-boot and his revolver in the holster suspended from the pommel. This discovery indicated to her that Lieutenant Wingate had not had time to take either weapon with him when he dismounted.

"It is my opinion that Hippy fell asleep and fell off," declared Emma, after they had completed their search of the clearing.

"Oh, what shall we do?" wailed Nora, wringing her hands. "Grace darlin', help me think. I can't think straight. Somebody suggest something."

"When did you first discover that his pony was lagging?" questioned Grace, turning to Miss Briggs.

"I should say that it was twenty or thirty minutes ago."

"Say half a mile back. It is possible that Hippy was unseated by coming in contact with an overhanging limb, though I do not recall having seen any low enough to b.u.mp one's head."

"We must go back and try to find him," said Miss Briggs.

"Yes," agreed Grace, her brow puckering in thought. "Anne, I think you had better remain here in charge of the camp. Get your rifles out and be on the alert. This affair looks suspicious to me. Shoot a signal if you need us in a hurry. Elfreda, will you go with me?"

Miss Briggs nodded.