For a few seconds he sat unable to move; then he stretched out his hand and began to shake Stobell.  He could have sworn that hands were fumbling at the tent.

“Eh?” said Stobell, sleepily.

Chalk shook him again.  Stobell sat up angrily, but before he could speak a wild yell rent the air, the tent collapsed suddenly, and they struggled half suffocated in the folds of the canvas.

CHAPTER XIX

Mr. Stobell was the first to emerge, and, seizing the canvas, dragged it free of the writhing bodies of his companions.  Mr. Chalk gained his feet and, catching sight of some dim figures standing a few yards away on the beach, gave a frantic shout and plunged into the interior, followed by the others.  A shower of pieces of coral whizzing by their heads and another terrible yell accelerated their flight.

Mr. Chalk gained the farther beach unmolested and, half crazy with fear, ran along blindly.  Footsteps, which he hoped were those of his friends, pounded away behind him, and presently Stobell, panting heavily, called to him to stop.  Mr. Chalk, looking over his shoulder, slackened his pace and allowed him to overtake him.

“Wait—­for—­Tredgold,” said Stobell, breathlessly, as he laid a heavy hand on his shoulder.

Mr. Chalk struggled to free himself.  “Where is he?” He gasped.

Stobell, still holding him, stood trying to regain his breath.  “They—­ they must—­have got him,” he said, at last.  “Have you got any of your pistols on you?”

“You threw them all away,” quavered Mr. Chalk.  “I’ve only got a knife.”

He fumbled with trembling fingers at his belt; Stobell brushing his hand aside drew a sailor’s knife from its sheath, and started to run back in the direction of the tent.  Mr. Chalk, after a moment’s hesitation, followed a little way behind.

“Look out!” he screamed, and stopped suddenly, as a figure burst out of the trees on to the beach a score of yards ahead.  Stobell, with a hoarse cry, raised his hand and dashed at it.

“Stobell!” cried a voice.

“It’s Tredgold,” cried Stobell.  He waited for him to reach them, and then, turning, all three ran stumbling along the beach.

They ran in silence until they reached the other end of the island.  So far there were no signs of pursuit, and Stobell, breathing hard from his unwonted exercise, collected a few lumps of coral and piled them on the beach.

“They had me over—­twice,” said Tredgold, jerkily;” they tore the clothes from my back.  How I got away I don’t know.  I fought—­kicked—­then suddenly I broke loose and ran.”

He threw himself on the beach and drew his breath in long, sobbing gasps.  Stobell, going a few paces forward, peered into the darkness and listened intently.

“I suppose they’re waiting for daylight,” he said at last.

He sat down on the beach and, after making a few disparaging remarks about coral as a weapon, lapsed into silence.