If that explosion reached them!... They must keep ahead of it at all costs. Ric opened the rockets wide, and gasped at the surge of power. These new rockets were blast proof indeed! Tal was at the stern ports now, watching the larger ship driving away from them. Soon it had vanished into the gray-blue distance. The explosion would be soon.... Minutes passed. Then it came. They saw it first, a blinding flash of light that seemed to encompass all of space within Phobos' shell! But it would be more minutes before they felt the actual concussion. They were speeding away recklessly, speeding _with_ gravity now! And before Ric quite realized it, they were nearing the outer shell again and he had to break speed. Then his heart sank within him. Due to that wild spin, he had lost direction! The huge air-lock, where Praana waited, was nowhere in sight. Precious seconds passed, as Ric brought the spacer skimming the inside of the shell like a pebble inside a bottle! Panic gripped him. This would be the end, if they didn't find that air-lock! It was the only passage to outer space. When the full concussion reached this shell, it would flatten them! He heard Tal shouting in his ear. "The city! There's the city!" He was gesturing frantically, far to the left. Ric headed for it recklessly and swept over the city at breakneck speed. The lock should be somewhere a few miles beyond.... Then they saw it. They glimpsed tiny pin-points of fire as Praana blasted the rockets of her ship as a signal to them. Ric braked with the forward tubes. As it was, he came into the wall with a crashing glide that sheared half of the underhull away. They climbed out, raced for the lock just as the first wave of onrushing air threatened to sweep them up. It became a hurricane. The full concussion would be right behind it! Praana was waiting and ready. They piled into the ship and without a waste motion Ric was at the controls. They swept deeper into the lock ... into darkness. Unbearable heat enveloped them. Already they were feeling the concussion! There came a moment of giddy acceleration, an unbearable pressure that sent the blood pounding in their ears. Then a pattern of starlight swept across their vision. Sharp crags loomed suddenly ahead ... they passed over them, a wild terrain dropped sheerly away, and their spacer became a fiery pinwheel of rocket blasts as they were hurled into free space! * * * * * Ric was fighting the controls, fighting the unbelievable pressure that threatened to black him out. He caught a glimpse of Phobos behind them, bursting apart in a blinding holocaust. Gradually, with alternate rocket thrusts, he managed to stop their wild spin. Then, dazedly, they turned to look.