Puzzled and disturbed by this strange phenomenon, he gave his ship a fresh burst of speed and headed straight for his island goal. With every second the peculiar howling sound, which at first was little more than a whistle, increased until it was like a fire alarm. Thirty seconds had not passed before an airplane such as he had never seen came shooting out of a large cloud to go darting across his path. “Lost its propeller,” was his first thought. “It will crash into the sea.” When suddenly the plane banked sharply, began to climb, and then came darting at him like a hornet, his astonishment knew no bounds. He was a good pilot. There were few better, and he had a cool head. Giving his ship all the gas it would take, he shot down in a vertical dive. With plenty of altitude between his plane and the water, he was safe for a second but what would happen after? A glimpse of the plane as it shot across the sky above him told that it carried no markings. “Nobody’s plane,” he thought. “A flying Dutchman of the sky.” Hardly had he thought this than he realized that, circling like a darting humming bird, the ship was preparing to come at him again. This time he resolved that in a way he should hold his ground. Dropping a few hundred yards he banked hard in an attempt to come up beneath the plane for a try at a burst of fire. But when he reached the spot the ship was some distance away. “Such speed!” he muttered. “Wonder if she’s armed?” Vain question. A burst of slugs swept across the sky. Holes appeared in his right wing. “Declaration of war!” he shouted. “Well, then, I accept the challenge.” He began an all but vertical climb to get above them in the hope of dropping on their tail. “If that creation has a tail,” he thought with a touch of desperation. “A regular headless horse of the air! No propeller, a sound like a siren. What can you expect?” One thing he could expect was speed. They were after him and climbing like the wind. They were nearly upon his tail before he knew it. Banking sharply to the left, he went into a terrific dive. As he flashed past them they fired from some swinging gun, and missed. “I’ll make the island before they get me or crash,” he swore to himself. Then he saw a cloud. It was just ahead of him, not large, but at least a haven. He darted into it, and for the moment was safe. But the enemy was persistent. The freak began crisscrossing the cloud. Circle as he might, Ted could not quite escape contact. There came the _rat-tat-tat_ of machine-gun fire. “Shooting at my shadow,” Ted guessed. “That’s a game two can play.” Ten seconds later, catching a dark streak passing through the misty cloud, he released a burst of fire. The shriek of the enemy plane changed instantly. Had he registered a hit? He dared hope so. But the fight was not over. The wild terror still circled, its shriek becoming sharper and more piercing each instant.