Only for a few seconds had he remained watching the negro, and wondering, with unpleasant thoughts, why the latter before leaping overboard had half drawn the knife from his belt and then resheathed it. Something like a suspicion passed through the mind of the youth. What could the negro want with a knife, if his object was to give help to the swimmer? Could a fiendish conception have occurred to the Coromantee, to lessen the number of those who might require food and water?
It is true the suspicion had barely shaped itself in the brain of the boy. Still, it had shaped itself, to be succeeded by a feeling of remorse for the wrong which he had done to Snowball in entertaining it. Almost on the instant did he become conscious of this wrong, by an object coming under his eyes and which at once accounted for the conduct of the Coromantee, that had seemed strange. Snowball was swimming towards Ben Brace,—not to destroy,—but with the intention of saving him.
From what? Was the sailor really in danger of sinking, so as to stand in need of support both for himself and his burden?
Little William did not put such an interrogatory. All his conjectures were ended. The peril threatening his patron,—and little Lalee as well,—was plainly outlined before his eyes, in all its frightful reality. That flattish, dark disc, with lunetted edge, rising erect above the surface, and cutting keenly through the rippling water, was an object not to be mistaken for any moving thing met with amid the ocean, save the dorsal fin of a shark, and William knew at a glance that such in reality it was.
He saw, moreover, it was the same he and little Lalee had so late been contemplating in security,—the dreaded zygaena: for through the translucent water he could distinguish its hammer-shaped head, and lurid eyes gleaming out from their protuberant sockets,—hideous to behold!
The boy now became spectator,—sole spectator,—of a scene of thrilling, even terrible interest. The characters in the drama were Snowball, the zygaena, and Ben Brace with his burden.
Just as William had arrived at the comprehension of the Coromantee’s behaviour, the dramatis persona were placed relatively to each other in a triangular position,—an isosceles triangle, in which Snowball and the shark represented the angles at the base, while Ben with his charge occupied the apex. The latter point was almost stationary, while both the former were moving towards it in converging lines, fast as shark and man could swim.
The situation was easily explained. The zygaena, hitherto holding its course ahead of the Catamaran, had become apprised of the catastrophe occurring among the crew. The plash occasioned by little Lalee as she was flung upon the water, and the heavier concussion of Ben’s body as he plunged overboard, had reached the monster’s ears; and, with that fell instinct peculiar to its tribe, it had suddenly turned in the water, and commenced swimming toward the wake of the craft; where it knew that anything, whether human or otherwise, falling overboard, must inevitably drift.
While passing the Catamaran towards the wake, Snowball had caught sight of its fan-like fin,—which apprised him of the direction it was taking, at the same time revealing to him its design.
The plunge which Snowball had made as he sprang out into the water had caused the zygaena to swerve from its course; and for some moments it swam towards him, as if determined upon changing the object of its attack; but whether not liking the looks of the Coromantee or frayed by his bold attitude in making directly towards it, it shied back into its former course, and kept on towards the others.