Mostyn handed over the weapon. The rowers laid on their oars and turned their heads to see what their companion was aiming at.
Black Strogoff was now only fifty yards ahead, swimming strongly in spite of his broken wrist, but close behind him was a dark, triangular-shaped object following the disturbed wake of the swimmer.
It was the dorsal fin of an enormous shark.
The pirate, unconscious of the dire peril that threatened him, swam steadily towards the schooner. Burgoyne, looking along the sights of the rifle, hesitated to fire, for the shark and the swimmer were in line with the muzzle. He might hit the shark, but the bullet would then ricochet and settle Strogoff into the bargain.
"Look out!" shouted the Third Officer. "Sharks!"
At the warning the pirate-lieutenant turned his head just in time to see the monster's dorsal fin disappear. The shark was turning on its back in order to seize its prey.
With a blood-curdling scream Black Strogoff threw up his arms and disappeared.
Thirty seconds later the boat was over the spot, where an ever-widening circle of ripples surrounded the blood-tinged patch that indicated the manner of Black Strogoff's death.
Burgoyne, pale under his tan, slipped the safety-catch of his rifle, laid the weapon in the stern-sheets, and resumed the tiller. As he did so he noticed that the boat's bottom boards and gratings were awash.
Kicking aside the stern-sheets grating, Alwyn felt for the plug. It was in position and jammed hard into the bung-hole.