Never in the two years of experience which had brought him to the important post of first torpooner had Ken failed to thrill at the sight which now met his eyes. Directly ahead, now that the _Narwhal's_ bow was turned in pursuit, but veering slowly to port, swam a pack of the twenty to thirty-foot dolphins which are called "killer whales," their bodies so close-pressed that they seemed to be an undulating wave of black, occasionally sliced with white as the fluke-thrusts brought their bellies into view. Their speed through the shadowed, gloomy water was equal to the submarine's; when alarmed, it would almost double. "Three more of 'em will fill our tanks," grunted Streight, his chunky face almost glowing. He bit on a plug of tobacco, his eyes never moving from the screen. "Now, if only we hadn't lost Beddoes.... Y' think you can bag three, Mister Torrance?" "Well, if three'll fill our tanks--sure!" grinned Ken. The other's eyebrows twitched suddenly. "They're speeding up!" he shouted, and then: "That torpoon ready, there? Good." His voice lowered again as Ken pulled his belt a notch tighter and snatched a last glimpse of the fish before leaving. "I want you to try for three, son," he said soberly: "but--be careful. Don't take fool chances, and keep alert. Remember Beddoes." Ken nodded and walked to the torpoon catapult, hearing Streight's familiar send-off echoed by the men of the crew who were nearby: "Good hunting!" * * * * * The idea of an underwater craft for the pursuit of killer whales--tremendously valuable since the discovery of valuable medicinal qualities in their oil--had been scoffed at by the majority of the Alaska Whaling Company's officials at the time of its suggestion, but the _Narwhal_ after her first two months of service had decisively proved her worth. She was not restricted to the open seas, now swept almost clean of the highly prized killers; she could follow them to their last refuge, right beneath the floe-edges of the Arctic Circle; and as a result she could bring back more oil than any four surface whalers. With a cruising radius of twenty-five hundred miles, she stayed out from the base until her torpoons had accounted for anywhere from sixty to eighty killers. One by one these sea-animals would be taken to the surface and there cut up and boiled down, until her tanks were full of the precious blubber oil. Ever farther she pressed in her quest for the fish schools, dipping for leagues into a silent sea that for ages had been known only to the whale and the seal and their kindred; a sea always dark and mysterious beneath its sheath of ice.