It was the footfall of a four-legged animal.

"So!" he e.j.a.c.u.l.a.t.ed. "I wonder what it is. If there were wolves down here I would say it was a wolf, but I don't believe there are." Then a minute later, "Well, whatever it is, I'm going to find out."

He whipped out his automatic and turned suddenly.

As before, not a single living thing was in sight, only in the gra.s.s a movement as before.

Without a moment's aim, he fired a single shot at the spot. It was an act born of fear and Billie knew it, but for the life of him he could not have done otherwise, so nervous had he become.

The report was followed by a cry of pain and an instant later there came running directly toward him out of the tall gra.s.s a figure so weird that Billie stood as one paralysed.

The figure was that of a man not more than two feet high, with long arms and a head of diminutive size. While it stood upright at times, at others it came forward on all fours. To Billie it seemed a cross between a man and a monkey.

Gathering his wits in an instant, Billie would have fired again--in fact, raised his revolver to do so, when the strange creature fell to its knees and raised its hands in supplication.

"By George!" exclaimed the lad as he stood with lowered weapon.

"What kind of a thing is this? I wonder if it can talk?"

Then as he took a step toward it: "I'm not going to hurt you.

Come here."

The creature arose to its feet and came slowly toward him. As it did so Billie noticed that blood was running from a wound in its scalp.

"Poor thing," he said. "That must have been where the bullet hit him. It was a close shave."

"Can you talk?" he finally asked.

The strange creature turned its head to one side and eyed him closely, but no sound came from its lips.

"It must be an ape of some sort," mused the boy; "but how did it become so tame?"

He slowly returned his automatic to its holster, thinking in the meantime how he could dress the creature's wound; but no sooner had his hand left his weapon than the ape sprang at him with the utmost fury. It landed on his shoulder, wound its legs about his neck, and with its long arms made a wild grab for the revolver.

Then began a strange and terrible struggle for the possession of the weapon. Even as he fought the beast, Billie realized that in some manner the ape had learned to fear firearms, but whether it had ever learned to use them he could not venture a guess. He felt certain if he could draw the weapon and point it at the ape, it would at once cringe in fear. What might happen if the ape should get possession of it, he could only imagine.

For a youth of eighteen, there were few whom Billie met that were his match physically, but this diminutive man-animal held him as in a vise. Billie exerted every ounce of his strength to free himself from the terrible hold, while the ape fought even more fiercely to retain its grip and to gain possession of the weapon.

It was a weird and fearful struggle waged there in the stillness of the tropical woodland--a stillness broken only by the occasional wild scream of the ape, or the hoa.r.s.e breathing of the boy as he fought to free himself from that horrible grasp.

The struggle must have lasted for two or three minutes--to Billie it seemed hours--when by a sudden wrench the lad managed to free his left arm sufficiently to get the beast by the throat. For an instant it loosed its hold on his right arm and that act decided the battle.

Finding his right arm free, Billie seized his revolver and without drawing it from the holster pulled the trigger.

At the sound of the shot, the ape uttered a plaintive cry, relaxed its hold upon the lad and fell upon its knees on the ground with its hands raised in supplication as previously.

"I ought to shoot you," declared the lad between his gasps for breath as he drew the weapon from its holster and pointed it at the animal, "but I won't. I'll take you with me and maybe I can sell you for enough to pay me for the scare you've given me. Now, march!"

He pointed with his finger down the track, but the beast would not stir.

"Don't you intend to do what I tell you?"

The animal perked up his head and kept his eye upon the revolver.

"Well," exclaimed Billie as he drew a long breath, "this is the limit. I can't make you mind and I won't hurt you. I guess the only thing I can do is to go and leave you."

Suiting the action to the word, Billie turned and started down the track, his revolver still in his hand.

He had not gone more than a dozen steps, before he heard the soft pat-pat behind him, and on looking back could see nothing but the waving gra.s.s to indicate the whereabouts of his erstwhile a.s.sailant.

"So I am to be followed, am I? Well, all right." Then, as an afterthought: "I wonder how I can catch him when I want him. I wonder if this will do," and he raised his weapon and pointed it toward the moving gra.s.s.

With the same plaintive cry which Billie had come to recognize as one of fear, the animal ran toward him and sank to his knees.

Billie smiled.

"It's all right, old chap. As long as I know how to handle you, why you can follow me right back to the train."

Again he started down the track at a brisk walk, it having just occurred to him that there might be something doing at the other end of his journey.

Twenty minutes later he reached the station at Pitahaya where he had expected to find Adrian and the three Mexicans awaiting him, but, as we know, they had gone on to the scene of the wreck. Not realizing just what had happened, but always on the alert for the unexpected, Billie, therefore, began an inspection of the station.

It did not take him long to discover that Pitahaya was little more than a siding with a one-room building, which was used as a freight house and a waiting room. It did not even boast of a station master.

"There must be some reason for having a building here," he mused.

"There must be some sort of a settlement around somewhere. But what's that to me? I might as well be jogging along towards Pachuca."

Then he bethought him of the ape, which he had no mind to lose after his exciting experience. But the animal was nowhere to be seen.

"I wonder if I could raise him with a shot," soliloquized Billie.

He raised his weapon, which he still carried in his hand, and fired aimlessly, while he turned his eyes in various directions, but there was nothing to be seen.

"Oh, well," he thought, "what's the difference? He'd just be a nuisance anyway. I might as well be trudging along."

He jumped off the station platform and proceeded down the track, filling the magazine to his automatic as he went. Then having finished the task, he returned it to his holster and once more began counting the ties.

"One, two, three, four, five, six----"

Bing! And a stone whistled by his head.

Billie turned, and as he did so a second stone from the same source struck him on the temple, and he fell to the ground.

A second later the ape sprang from a palm beside the station and ran toward him, stopping every few feet to see if the lad would rise.

When within a few feet of the prostrate lad the animal made a leap and landed upon his body. In another instant it had gained possession of Billie's weapon, which it examined curiously for a moment, ere it sprang away and stationed itself some two rods distant, where it sat watching with the weapon aimed directly at him.

For perhaps five minutes the two retained their relative positions and then Billie began to regain consciousness. Several times he moved uneasily and then he suddenly sat up and looked around.

"I wonder what happened," he finally thought, and then he became conscious of a pain in his head.