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. Jack’s blood boiled at the insult. It acted as a brace to his sinking heart. As the man lunged at him the boy’s hand struck up the arm that held the knife and the weapon went spinning into the night. But the Mexican, a large man of uncommon strength and activity, did not cease his attack. He rushed at Jack as if to annihilate him. This was just what Jack wanted. The angrier the Mexican was the worse he would fight, as Jack knew. He met the onrush with coolness, and succeeded in planting two good blows on the man’s body. But muscular as Jack was the blows appeared to have little effect on the Mexican. He tore in more savagely than ever. Without his knife the Mexican was not much of a fighter. He knew nothing of the art of boxing, and Jack’s “gym” training stood him in good stead. At last, in one of the Mexican’s frantic rushes, Jack’s fist met the point of his chin with deadly effect. With a wild swinging of his arms the fellow reeled backward. He would have fallen from the raft into the current had not Jack leaped forward and saved him. But the Mexican was a formidable foe no longer. Jack’s blow had effectually stunned him for a time, and as the boy saved him from pitching overboard he sank in a heap on the floor of the raft. In the first opportunity he had had for observation of his situation since the raft had got loose, Jack looked about him. Then, for the first time, he realized that the rough craft was proceeding at an extremely swift rate. It was spinning round dizzily, too, as though caught in some sort of whirlpool.