Marie's eyes opened wide at this. "But how could that be?" she asked. "Surely no one from our earth has made the trip to one of the other planets?" "It may be that someone has," replied Hart. "Do you remember Professor Oradel? Remember, about ten years ago, I think it was, when he and a half dozen or more of extremely radical scientists built a rocket they claimed would reach the moon? They were ridiculed and hissed and relegated to the position of half-baked, crazy inventors. But Oradel had a large private fortune, and he and his crowd built themselves a workshop and laboratory in a secluded region in the Ozarks. Here they labored and experimented and eventually the rocket ship was constructed. No person was in their confidence, but when the machine was completed they issued a statement to the press to the effect that they were ready for the voyage to the moon, and that, when they returned, a reckoning with the world was to be made for its disbelief and total lack of sympathy. Again the press subjected Oradel to a series of scathing denunciations, and the scientific publications refused to take cognizance of his claims in any way, shape or form." * * * * * "Then, one night, a great rocket roared into the heavens, leaving a terror-stricken countryside in the wake of its brilliantly visible tail. Several observatories whose telescopes picked up and followed the trail of the contraption reported that it described a huge parabola, mounting high into the stratosphere and falling back to earth, where it was lost in the depths of the Pacific Ocean. There the thing ended and it was soon forgotten. But I believe that this rocket ship of Oradel's reached Mars or Venus and that the peoples of whichever planet they reached have been prevailed upon and prepared to war upon the world." "That would explain their knowledge of our languages and codes." I ventured, "and would likewise account for the fact that the first of our ships to be attacked were those carrying large shipments of currency. Though if these were destroyed by the fire columns, I can not see what good the money would do them." "Don't believe the first three were destroyed," grunted Hart. "You'll remember that in these cases the pillars of fire, or whatever you want to call them, were of a cold light, whereas now they are viciously hot and leave behind them the terrible destructive fires that spread and spread and seemingly never are extinguished. No, I think that the force used is something of the nature of an atom-disrupting triad of beams and that these set up the column as a veritable tornado, a whirling column of roaring wind rushing skyward with tremendous velocity. The first ships, I believe, were carried into the stratosphere and captured intact by the enemy.