With one hand in readiness on the control lever, which resembled in appearance and operation the joystick of an airplane, and his feet on the bar used for steering in a lateral plane, he kept his eyes fixed on the receding bulk behind. Jan had handed him one of the two pairs of binoculars which she had just found in the supply compartment. Austin knew what to expect from the direction of the _Selba_, and it came well within schedule. A flash of green fire spurted from the foredeck of the ship. It showed up with startling vividness against the jeweled sable of the void. Abruptly Shelby drew the control lever back. In response to his movement the rocket nozzles, now deflected from alignment with the central axis of the craft, sent it into a steep climb. The terrific angular acceleration seemed intent on forcing the two fugitives straight through the metal floor. It drew the blood from their faces and made them grow pale and giddy. But they escaped being struck by the torpedo. It exploded a hundred yards beneath the flier's keel. Fragments of it banged against the hull. In rapid succession other flashes darted from the _Selba_, which had dwindled to a silvery speck far to the rear. But still those missiles, directed by incredibly delicate sighting mechanisms, and hurled at almost the speed of light, continued to score remarkably close to their target. If it had not been such an elusive target they most certainly would have blasted it to fragments. But Shelby, skilled as were most of the men of his time, in the handling of small space craft, was able to endow his flier with much of the agility of an alarmed dragon fly. Darting, weaving, zigzagging, yet always keeping its general course fixed toward Mars, it careened away. Always it was ringed by an aura of green flashes. However, good fortune is seldom perfect. The tempered duralumin plates of the flier managed to withstand the force of all of the torpedo fragments which showered them--with one exception. One dart from Hekalu's ship exploded barely fifty feet to the right of the fugitive craft, and a flying chunk of steel sent it pitching and tumbling through the ether. When the two bruised occupants had regained their equilibrium they heard a faint hissing above the roar of rockets. They knew that there was but slight chance that the _Selba_ could do them any further harm, for though the torpedoes continued to come, the distance between the two vessels was now so great that a damaging shot was almost an impossibility. Nevertheless, the present situation was serious enough. A leak! Fixing the nose of the flier toward the Red Planet, and locking the controls, Shelby left the pilot's seat to determine the extent of the damage, while Jan searched the supply compartment for something with which to repair it. There was a deep dent in one of the ceiling plates and a thin wriggly crack through the center of it--not an easy job to patch that out in space under the best of circumstances.