Just as dawn was breaking Phil Branscombe went to the open window of his hut and listened intently. Then he turned to Withers, his "cabin-mate".
"Old bird," he announced, "I hear an aeroplane."
"The Malfilio's seaplane returning, I expect," rejoined Withers, stifling a yawn.
"Wrong, my festive!" exclaimed Phil ten seconds later. "They're British seaplanes."
Of that there was no doubt. Flying high they were already in the rays of the sun, while the ground was yet in shadow—three large biplanes fitted with both floats and landing-wheels. Above the island they separated, one passing over the harbour, another circling above the Observation Hill, and the third, swooping down to within a couple of hundred feet, described figures of eight above the prisoners' huts.
Presently a powerful Aldis light flashed from the third seaplane. Blinking rapidly it Morsed the following, "Are prisoners compelled to man batteries?"
Regardless of Fernando's warning, at least half a dozen men signalled replies, using any fabric nearest to hand to "flag-wag" the reassuring message that all hands were within the limits of the fence.
"O.K." flashed the seaplane's lamp, and then the information was promptly transmitted by wireless to the Armadale.
Meanwhile the second seaplane had dropped a message, with distinctive streamers attached, close to the Observation Hill. It was an ultimatum, ordering the garrison to surrender at discretion, and signify the same by hoisting a white flag within thirty minutes of the receipt of the demand.
But the ill-advised action on the part of the machine-gunners in the block-houses destroyed the chance of the pirates surrendering without bloodshed. The seaplane over the prisoners' camp offered an irresistible bait, and a burst of machine-gun fire was directed upon the rapidly-moving aircraft.