Then the alarm bell began to ring again.
"There's someone climbing the path," whispered Ellerton, when the din had died away.
"I wish Terence would hurry up with the searchlight; we could then see who the intruders are. There it is again," as the clanging of the bell commenced for the third time.
In his natural anxiety and haste, Terence fumbled over his task, but at length the carbons fused and the giant beam of the searchlight threw its dazzling rays seaward. Then, trained by Donaghue's guiding hand, it swept the lower terraces and the beach, but neither hostile canvas nor lurking bloodthirsty warriors came within its blinding glare.
"There's someone moving down there," exclaimed Andy, pointing towards the foot of the steep path. "See! To the right of that great boulder."
"Hanged if I can," muttered Ellerton. Nevertheless he took aim with his rifle at the spot indicated by his chum.
"It's only the shadows thrown by the moving beam," said Mr. McKay. "Terence, keep the light steady for a moment, will you?"
The now stationary ray revealed the fact that some moving object was creeping cautiously over the rock-strewn beach immediately at the end of the path.
"There's someone down there," whispered Ellerton, and almost as he spoke the alarm bell resumed its shrill warning.
"I'm going down to see who or what it is," announced Mr. McKay, leaning his rifle against the stockade and drawing a revolver.