There were no scouts from the Sirian fleet--yet there should have been, for over a thousand ships had been following them, far behind. None ever reached Earth to warn the fleet. Every one of them was destroyed. But when the Sirian fleet was well on its way--it turned--and headed _for Venus_! They had purposely let that one scout reach the Solarian fleet with the news that the fleet was headed for Earth--then they redirected their course. The scouts from the Solarian fleet did reach Earth--but soon after the last of the scouts following the Sirian fleet had been destroyed, their radio barrage was lifted. All the ships on Venus were concentrated on Earth, and Venus was left unprotected. Twenty hours after the fleet had turned back, the radio barrage was again lowered over the System. It was ten hours later that the Sirians reached Venus. While the radio barrage had been lifted, Waterson had had an idea that there should be some protection for the planet. It did not seem that the planet should be completely stripped of its defenses, and he had suggested that at every city great Dis ray machines of the sixty-mile range type be set up. His suggestion was followed, and at every city on Venus the great machines were installed. There were many of them now, for during the hundred hours the main fleet was in flight the new machines had been put on a quantity production basis. But all the ships that were equipped with them, were sent to the defense of the unattacked Earth! And it was those machines that prevented the landing of the Sirians. They came to the night side of the planet, of course, coming from Mars. It would be thirty hours before they would be expected on Earth--thirty hours before the main fleet would reach the planet--and then there would be the 160,000,000-mile trip to Venus if they were to get there in time to rescue the planet. But the Sirians could not approach within beaming distance of the cities, and all those that did try to do so, were brought down as a cloud of powdery dust. It was Waterson's caution that saved the billions of people on Venus.