"Come here, will you, Morey," called Arcot. In a moment Morey joined his much worried friend. "That artificial matter control won't work through ray screens. The Thessians never had to protect against moleculars here, and didn't have them up--hence the destruction wrought. We can't take our screen down, and we can't use our most deadly weapon with it up. If we had a big outfit, we might throw a screen around the whole ship, and sail right in. But we haven't. "We can't stand ten seconds against that fleet. I'm going to find their base, and make them yell for help." Arcot snapped a tiny switch one notch further for the barest instant, then snapped it back. They were several millions miles from the planet. "Quicker," he explained, "to simply follow those ships back home--go back in time." With the telectroscope, he took views at various distances, thus quickly tracing them back to their base at the pole of the planet. Instantly Arcot shot down, reaching the pole in less than a second, by carefully maneuvering of the space device. A gigantic dome of polished relux rose from rocky, icy plains. The thing was nearly half a mile high, a mighty rounded roof that covered an area almost three-quarters of a mile in diameter. Titanic--that was the only word that described it. About it there was the peculiar shimmer of a molecular ray screen. Morey darted to the power room and set his apparatus into operation. He created a ball of matter outside the ship and hurled it instantly at the fort. It exploded with a terrific concussion as it hit the wall of the ray screen. Almost instantly a second one followed. The concussion was terrifically violent, the ground about was fused, and the ray screen was opened for a moment. Arcot threw all his moleculars on the screen, as Morey sent bomb after bomb at it. The coils supplied the energy, cracked the rock beneath. Each energy release disrupted the ray-screen for a moment, and the concentrated fury of the molecular beams poured through the opened screen, and struck the relux behind. It glowed opalescent now in a spot twenty feet across. But the relux was tremendously thick. Thirty bombs Morey hurled, while they held their position without difficulty, pouring their bombs and rays at the fort. Arcot threw the ship into space, moved, and reappeared suddenly nearly three hundred yards further on. A snap of the eyes, and he saw that the fleet was approaching now. He went again into space, and retreated. Discretion was the better part of valor. But his plan had worked.