The mere mental strain involved was exhausting. Not only had Bob the thousand legitimate devices of the ring to look out for, but he never knew when to expect a vicious jab below the belt, or a nasty butt from the head. And always in the back of his mind was a fear that those murderous spikes might at any moment strike deeply, maimingly at the vital spot for which they had been aimed twice before. By this time, of course, every “river hog” within sight had raced up, and the combatants were surrounded by a ring of eager spectators, several deep, which swayed and moved and billowed out elastically as the fight progressed. A number of them were evidently in sympathy with Schaeffer, and kept urging him to go in and win, but the majority remained silent save for occasional muttered ejaculations when a particularly clever or vicious blow struck home. Moose, his small black eyes glistening, but otherwise as stolid and unmoved as ever, managed constantly to retain his position in the front row. For a long time Bainbridge kept his opponent in hand. Always the strain of waiting, expecting, planning to meet the unknown foul, was uppermost in his mind, to the exclusion of almost everything else. He knew in an intuitive sort of way that he was fighting well. He had landed several blows which staggered the man, and the fellow’s face, from which Bob never for an instant withdrew his eyes, was cut and bleeding. That proved little, however. He was evidently the sort that could take any amount of punishment, and come up for more. His wind seemed to be quite as good as Bob’s, and at length the latter was conscious of a single flash of doubt regarding the issue. What if he should not win, as he had determined in the beginning? What if Schaeffer should, by fair means or foul, manage to knock him out? It would not be like an ordinary knock-out--simply the end of a fairly fought contest to decide which of two men is the better scrapper. He would be helpless for a space, and in the power of this cur who had thus far stopped at nothing. Moose could accomplish little on his behalf when opposed by the crowd of spectators, all of whom seemed, from what Bainbridge had caught of their comments, to be on Schaeffer’s side. The thought of what might happen was not a pleasant one, and possibly it was that which led to Bainbridge’s undoing. He had so far instinctively avoided clinches as being favorable to fouls, but now, with his mind for a second partially distracted, after delivering a left-hand jab he did not spring back as swiftly as he might have done. The riverman took instant advantage of the chance, and leaped forward, gripping Bob’s wrist. In an instant Bainbridge had wrenched it away, but not too soon to prevent that close contact which he felt to be so dangerous. “He’ll try something dirty now,” flashed through Bob’s brain. “I knew it! No, you don’t--now.”