He pointed astern. Twenty yards away was the triangular dorsal fin of a shark.
"The brute," ejaculated Olive, with a slight shudder. "I hope he goes off soon."
But the girl's wish was not to be fulfilled. If the shark had been chasing the flying fish he no longer did so. Perhaps he scented promising and more satisfying fare, for without any apparent effort he began to follow the boat, rarely increasing or decreasing the distance.
"Hang the shark," exclaimed Peter. "Here, Olive, is a chance to show what a good shot you are."
He handed the girl his automatic. Without hesitation Olive took the somewhat complicated weapon. Peter noted, with a certain degree of satisfaction, that she handled it fearlessly, and at the same time with proper caution. He had no cause to duck his head because of the muzzle pointing in his direction.
"Don't forget to release the safety-catch," he said.
"I've done so already," rejoined Olive, pulling back the mechanism that performed the double action of cocking the pistol and inserting a cartridge into the breech.
It was not an easy target, even at twenty yards. Not only was the boat yawing, but the dorsal fin of the shark was constantly on the move.
The pistol cracked. Mostyn, intent upon preventing the boat from gybing, had no opportunity of seeing the result of the shot. The girl, replacing the safety catch, handed the weapon back to its owner.
"Missed it, I'm afraid," she said. "But there's one good thing—the shark's disappeared."