The Serena swung sound, and floated motionless on the calm sea. As far as could be seen there was no sign of her sinking. Some of the men rushed for the boats, only to be driven back by Cervillo and his officers, who, revolver in hand, did not hesitate to check the rush by the strongest measures. Finding that escape was impossible, the pirates were goaded into active resistance, and, with rifles and pistols, they took refuge behind the shattered bulwarks to await the approach of the scout's boats.
The Cerberus had lost way, and was lying barely half a mile on the Serena's starboard quarter. Into her boats swarmed the active bluejackets, eager to add to the traditions of the Service by capturing the pirates in the good old-fashioned style.
Secretly regretting that he was not taking an active part in the boarding of the Serena, Drake decided not to miss a close view of the operations. So the Mosquito, her speed reduced until it was only just sufficient to enable her planes to resist the action of gravity, descended to a height of about two hundred feet above the sea, and hovered in circles above the crippled vessel.
So intent were the pirates upon the approach of the boats that the presence of the aerial craft was entirely forgotten. Drake could see that Cervillo was pacing the deck in an irresolute fashion. At one moment he would speak to some of the men and point to their antagonists, at another he would halt hesitatingly at the top of the companion.
Nearer and nearer came the British seamen. Now they were within effective range of the revolvers. One or two of the pirates stood up ready to fire, but Cervillo restrained them, gave one swift, comprehensive glance over the side, and dived down the ladder.
In an instant Drake realised the pirate Captain's intention.
"Back oars all!" he shouted to the boarders. "Back for your lives!" And ordering the planes to be tilted, he placed a safe distance between the Mosquito and the Serena.
He was barely in time. With a roar and a fierce blast of flame the yacht's magazine exploded. A dense, black cloud of smoke, mingled with fragments of charred and splintered wood, was hurled high into the air.
Instinctively Drake thrust over the lever actuating the elevating planes, and the aerial craft leapt upwards. The next instant the little vessel was enveloped in an eddying vapour, so opaque that from where the lieutenant stood the bow was lost to view. For a few seconds the Mosquito oscillated violently. Fragments of charred timbers came perilously near the fragile planes. Well-nigh blinded and choked by the dust-laden fumes that, caught by the swiftly whirling propeller, were dashed into the lieutenant's face, Drake lost all idea of what the Mosquito was doing—whether the vessel was soaring or plunging disabled towards the sea.
Then it was like a train emerging from a tunnel; the blackness began to give place to subdued light, till with a whirr the aero-hydroplane cleft the edge of the cloud of smoke, and gained the pure air beyond.