"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." "Scared stiff, if not hit," rejoined Peter. "Do you mind hanging on to the tiller, while I clean out the barrel?" The day wore on. At six o'clock Peter roused one of the lascars, and told him to take on for a couple of hours. Already the tent had been rigged amidships, while the jib--useless, or nearly so, while running--had been employed as a sun-screen for Preston. The sun sank to rest, its slanting rays turning the hitherto blue sea into a pool of liquid, ruddy fire, that gave place to a spangled carpet of indigo as the long undulations reflected the starlight. Away in the west the young moon was on the point of setting. It was the sort of sub-tropical evening that made the discomfort of the open boat pale by its soothing influence. At eight Peter "took over". He had no desire for sleep, and was quite content to keep watch until relieved at dawn by one of the lascars; but he was somewhat surprised to find that Olive was likewise disinclined to turn in. They watched the crescent moon dip behind the horizon; they saw the stars pale as a slight mist rose from the waters of the Indian Ocean, and the starlight give place to a darkness broken only by the feeble rays of the binnacle lamp. By this time the wind had dropped to a gentle breeze on the port quarter, and there was no longer any risk of gybing. The erratic movement of the dead run had given way to the steadier "full and bye", with sufficient "kick" in the helm to make steering a pleasure rather than a monotonous routine. Suddenly the boat quivered and heeled over to starboard. The shock was sufficient to rouse the sleepers. "Aground!" exclaimed Olive. Peter put the helm down. The boat responded instantly to the action of the rudder. "No," he replied. "We've hit something. Wreckage, perhaps." "It's a fish!" declared the girl, as with a trail of phosphorescence a huge object darted under the keel and disappeared in the darkness. "That shark." "Or another one," rejoined Peter. "There's one blessing: it isn't a whale. Chup rao!" he called out to the jabbering lascars. In two or three minutes the awakened members of the boat's crew had relapsed into slumber. Peter swung the boat back on her course, and handed the tiller to the girl. "I'll have a cigarette, if you don't mind," he said.