At the same instant that Jack spied them the men became aware of the intruder on their raft. They did not dare to fire the weapons they carried, owing to the nearness of the Rangers; otherwise they would undoubtedly have done so. Instead, they made a simultaneous leap at Jack, the leader aiming a savage blow at him.

The boy dodged the man’s swing, springing backward on the raft. The contrivance had not been securely fastened to the bank. In fact, it had merely been tied carelessly up at the water’s edge. Jack’s sudden spring gave the raft a violent jolt. The current caught it and whirled it round as the strain came upon one side of it.

Before either Jack or the Mexicans exactly realized what had occurred, the raft was swept out into midstream, the current hurrying it along swiftly.

But Jack was not alone on the swaying, pitching craft. The Mexican who had aimed the blow at him had had one foot on the raft when Jack’s backward spring caused it to drift from the bank. By a desperate effort he had managed to maintain a foothold, and now he was crouching back on his haunches like a wild–cat about to spring, while in his hands gleamed a wicked looking knife.

Jack had just time to see this when the fellow, hissing out a torrent of Spanish oaths, sprang at him. Jack dodged the knife blow, and before the Mexican could recover his equilibrium the boy’s fist had collided with the lower part of the Mexican’s jaw.

The blow was a heavy one, and had landed fair and square. With a grunt of pain and rage the fellow reeled backward, almost pitching off the raft. But in a jiffy he recovered from his shock and rushed at Jack, snarling like a wild beast.

The boy realized that he was in for a fight for life, and in that moment he bitterly regretted the curiosity that had caused him to board the raft, although he had done it with the idea of performing a service for the Rangers. Now, however, he found himself facing a desperate situation.

Unarmed, and alone, he was on a drifting raft with an armed and singularly ferocious foe.

“Yankee pig!” snarled out the Mexican, as he flung himself at the boy.