The men in the machine behind sat white-lipped, tense, as the whirling shocks of sudden turns at terrific speed twisted the gyroscopic seats around like peas in a rolling ball. Up, down, left, right, the darting machine ahead was twisting with unbelievable speed. Then suddenly the nose was pointed for the zenith again, and with a great column of flame shooting out behind him, he was heading straight toward space! "If he gets there, I lose him, Morey!" said Arcot. The terrific acceleration of the climb seemed to press them to their seats with a deadly weight. It was labor to talk--but still the car ahead shot on--slowly they seemed to be overhauling him. Now that the velocities were perforce lowered by the effects of gravity, and the air resistance of the atmosphere was well nigh gone, only the acceleration that the human body could stand was considered. The man ahead was pushing his plane ahead with an acceleration that would have killed many men! Slowly the acceleration of the machine was falling. Arcot pushed the control over to the last ampere, and felt the slight surge, as greater power rushed through the coils momentarily. Soon this was gone too, as the generator behind faltered. The driving power of the atmospheric heat was gone. More than sixty miles below them they could see the Earth as a greenish brown surface, slightly convex, and far to the east they could distinguish a silvery line of water! But they had no eyes but for the column of shooting flame that represented the fleeing raider! Out in airless space now, he was safe from them. They could not follow. Arcot turned the plane once more, parallel to the Earth, watching the plane above through the roof window. Slowly the machine sank to the fifty-mile level, where there was just sufficient air to maintain it in efficient operation. "Well, he beat us! But there is only one thing for us to do. He must hang there on his rockets till we leave, and we can hang here indefinitely, if we can only keep this cabin decently warm. He has no air to cool him, and he has the sun to warm him. The only thing that is worrying him right now is the heat of his rockets. But he can throw most of that out with the gases. Lord, that's some machine! But eventually his rockets will give out, and down he will come, so we'll just hang here beneath him and--whoa--not so fast--he isn't going to stay there, it seems; he is angling his ship off a bit, and shooting along, so that, besides, holding himself up, he is making a little forward progress. We'll have to follow! He's going to do some speeding, it seems! Well, we can keep up with him, at our level."