The last day came. For two weeks we had been ready to move aboard whenever the alien force brought the frozen night again to earth. I had been living in it, while Sam spent most of his time in the laboratory. I whiled the time away by wandering on the beach, bathing in the surf, or dreaming idly. I tried to believe I did not care too much. I tried to think I could go on serenely, the last man alive, forgetting the dead earth--happy in my dreams of the Green Girl! CHAPTER VII The Globe of Crimson Doom For some time I had felt that Sam was afraid of something, of a danger more personal than the freezing of the earth. He had said little about it, but from his hints I gathered that he thought the mysterious force he was struggling against might do something to sweep him and his machine out of the way. He spent hours alone in the little room, with the apparatus that registered new force in the ether, manipulating his switches and dials, with the phones on his ears, and his eyes fixed on the color screen, listening and watching intently--for what? There was no man on earth with enough knowledge of science to follow him. None could have understood his explanations, even if he had given them. So the world will never know. It was just after sunset that the amazing thing took place that showed the full power and alertness of the incredible force that menaced the earth. I was sitting in a folding chair on the narrow white metal deck of the machine, leaning back against the squat conning-tower, with the black muzzle of the little gun sticking out over my head. I had a book in my hand, but it was closed, and I was gazing out at the sea. Sam was still at the house, although it was past our usual supper time. Suddenly my attention was attracted by a faint hail. I glanced toward the cottage and saw him running toward me at a desperate pace, head down and legs working like pistons. Though I was unable to imagine what the matter might be, I got up, opened the hatch, carried down my chair and started the motors, in case he might want to move the machine. In a moment I heard him scrambling up the ladder at the side, heard his quick footsteps across the deck. He dived into the room, shouting breathlessly, "It's coming! Quick! Start--" Before I could move, he had brushed me from the instrument board. The heavy throbbing drone of the hydrodyne units rose higher, and in an instant the Omnimobile had lunged forward, with a great rattle and clanking of metal, so suddenly that I fell against the wall. I was amazed at the speed we developed. Sam was not sparing the machinery. The clanging roar was almost deafening. The whole machine vibrated to the engine beat, and it rolled and tossed so much that I could hardly recover my feet. With face set and expressionless, with blue eyes straight ahead, Sam stood with his hands on the levers.