In the midst of this futile effort, Mahoney chanced to drop his glance into the depths. There he caught sight of something that arrested him, making him forget for the moment even the tortures of his thirst. In the deepest green, at the very confines of his vision, a gigantic shape came faintly into view. It stirred, and grew more distinct. Motionless he peered down upon it, striving to make out what it was. His sea lore, more abundant than exact, did not inform him as to whether or not the shark had any enemies to fear; but his imagination, always finding free play in the mysteries of the deep sea, was hospitably ready for any marvel. With fantastic expectancy he watched the sinister form of the strange creature, as it slowly, and stealthily floated upward.
Presently he recognized it, having caught glimpse of its like once before in a deep lagoon of the Ladrones. It was not altogether dissimilar to the great shark basking above it, but slenderer in build, and with a pair of curious lateral fins outspread like broad, blunt wings. The most conspicuous difference was in its head, which was broad and blunt like the fins, and armed with a kind of two-edged saw, perhaps eight inches in width, projecting from its snout to a length of about four feet. The tip of the saw looked as if it had been chopped off square. Down both edges ran a series of keen, raking teeth. It was the mysterious and dreadful sawfish, perpetrator of fabulous horrors.
Mahoney was afraid to move a muscle, lest he should arouse the shark and put it on its guard. The eyes of the stranger stared up with a dead coldness at the bulk of the sleeping monster on the surface. More rapidly now, but still almost without movement of fin or tail, the ominous form rose through the transparent flood, till Mahoney could fairly count the teeth on its awkward-looking but hideous weapon. Directly beneath the shark the stranger came, till at last there was no more than the space of a few feet between the two giant shapes. And still the shark slumbered. Mahoney held his breath. Then the sawfish rolled over on its side, turning one edge of the saw toward the surface. For an instant it hung so, poised and still. Then the fins and flukes heaved together, the long bulk shot forward and upward, and the living saw cut straight across the belly of the shark, deeply and cleanly, under the urge of that tremendous thrust.
"DIRECTLY BENEATH THE SHARK THE STRANGER CAME."
Mahoney cried out, shuddering at the horrible and unexpected sight. The shark was completely disembowelled. With a gigantic convulsion it sprang almost clear of the water, which was instantly dyed with blood. Mahoney now looked for a battle of Titans to follow. But in truth the battle was already over. The victim made no attempt at retaliation. It did not even seem to see its foe, or to know what had stricken it. For a few seconds it lashed the surface convulsively. Then it dived, plunging straight downward to die unseen in some rayless cavern of the deeps.
With a leisurely zest which turned Mahoney sick, the monster guzzled its meal, then swam up and nosed inquiringly along the fringe of barnacles. Nothing there seeming to interest him, he turned with a disdainful sweep of his huge flukes and bored his way slowly downwards toward the unknown deep whence he had so mysteriously come. Unstirring, held fast as if in a hideous dream, Mahoney watched the dull gray-black form grow green, and spectral, and faint till at last it vanished. For a brief space he continued to stare after it, picturing it in his fevered imagination when it had sunk far beyond any reach of sight. At last, as if tearing himself free from a horrid spell, he drew a long breath and lifted his eyes to the horizon.
There, in full view, but too far away to notice such a speck among the waves as Mahoney on his bit of wreck, was a small freight-boat, steaming past at a leisurely pace. Mahoney was himself in an instant. He realized that the sawfish had freed him from his dreadful jailer. With his knife between his teeth he dived beneath the upturned sloop and fell to cutting ropes and lashings with a cool but savage haste. In half a minute he reappeared, gasping, but not discouraged. After two or three deep breaths he dived again, and this time when he came up, he brought the long slender pole of the gaff with him. With frantic eagerness he hoisted the white pennon of his shirt and coat, thanking Heaven that the gaff was so long. He was about to lash the pole to the bulwarks with his belt, when he remembered that there was not wind enough to run out the signal. Lifting it in both hands as high as he could, he waved the flag wildly over his head in great arcs and sudden violent dips. Would the lookout on the steamer see? Or seeing, would he understand? Mahoney felt his strength suddenly failing, as a wave of despair sucked up at his heart. It was all he could do to keep the signal moving. Then, at last, he saw that the long line of the steamer's broadside was shortening. Yes,—she was coming, she was coming. Tremblingly, with fingers that fumbled, he lashed the staff to the bulwark, and sank panting upon the deck.