In all probability, it was this cynical laugh which saved his life, but defeated his immediate object. Lawless had realised that if the man fired at him it must inevitably attract the attention of those on board the _Mars_--for revolver shots in mid-air would be hardly likely to pass unnoticed--and they would at once open fire with the anti-aircraft guns. But the same thought had evidently occurred to the other, for, instead of firing, he slipped the revolver back into his pocket. Lawless braced himself for the coming struggle, and twisted his legs round some wire guys to secure a firmer grip of the machine and leave his arms free. Giving a quick glance below, he saw the lights of the _Mars_ and her attendant destroyers standing out like tiny specks in a gulf of unfathomable blackness. The two red lights of the _Black Diamond_ were no longer visible, and he concluded that, having launched the waterplane, she had proceeded on her way. To the left he could see a searchlight, which he assumed to be operated from the _Knat_, rapidly sweeping the horizon in great semi-circles. The whole panorama passed before his eyes like a flash, and a moment later he had come to grips with his antagonist. With arms enlocked and faces almost touching, the combatants swayed gently to and fro, as though testing each other's strength. Then, loosening their hold, and drawing a little apart for a second, they closed again, and this time they wound their arms about each other like bands of steel, till the terrible pressure made their veins stand up like whipcord, and their breath came in short, choking gasps. But neither could get sufficient advantage over his adversary to swing him off, and more than once it seemed as if both of them must tumble into the sea beneath. Had the pilot been able to come to the assistance of his companion, Lawless would not have stood a dog's chance; but, fortunately for him, the man had all he could do to maintain control of the machine and prevent it from capsizing under the constantly shifting weight of the opponents as they swayed dangerously from side to side. Suddenly, from a point seemingly immediately beneath them, came a faint bellowing sound, which Lawless at once recognised as the _Mars_' syren. Apparently his antagonist recognised it also, for, throwing caution to the winds, he flung his body forward, carrying the Lieutenant with him so that they both nearly went over the side with the sudden impetus.