"A threat to freeze the Croton reservoir and cut off New York City's water supply if an answer to his previous demands is not given within forty-eight hours! And he can do it! Mr. Gerrod, you've simply got to settle this business. New York would go crazy if the people knew this. There'd be no way to supply the water the city has to have. And seven million people without water----" Teddy smiled grimly. "I'm going to try. Professor Hawkins is usually right, and we ought to be able to do something about this berg." A second messenger came up and saluted. "Sir, Lieutenant Davis reports that the plane has been recovered and Lieutenant Curtiss' body examined. There are no bullet marks, and the body seemed to be frozen solidly. He cannot say, as yet, what caused Lieutenant Curtiss' death." "Frozen," said Teddy laconically. "In mid-air?" asked the commandant sharply. "And in a fraction of a second, wearing heavy aviator's clothing?" Teddy nodded, and buttoned up the huge fur coat in which he was enveloped. "I'm ready to start off now, if the sledges are." The little party moved away from the shore. The heavy mist still hung over the expanse of ice, but near the shore the ice was thinner. The sledges were roped together, and Teddy walked at the head. The party tugged at the ropes on the sledges, puffing out clouds of frosty breath at every exhalation. Teddy had taken the compass bearings of the steam plume, and after he had gone a hundred yards from the shore the wisdom of his course became apparent. They were completely surrounded by a thick fog in which objects five yards off were lost to view. Teddy, leading the small column, could not be seen except as a dim and shadowy figure by the men hardly more than two paces in his rear. He referred constantly to his compass, and once or twice glanced at the thermometer he had strapped on the sleeve of his great coat. "Forty degrees," he murmured to himself. "And in New York it's eighty-four in the shade. The ice must be colder still because it's dry and hard." The party toiled on. Presently small snow crystals crunched underfoot. "Frozen mist," said Teddy, and glanced at his thermometer. "H'm! Twenty-two degrees. Ten below freezing." The party stopped for a breathing spell. "I hope you men smoke," said Teddy, "because it's going to be cold a few hundred yards farther on. We'll come clear of this mist presently. If you smoke, and inhale, it'll probably warm up your lungs a little. You don't need it yet, though. Any of you who haven't pulled down the flaps of your helmets had better do so now."