As soon as she was fairly on her course, Arnold gave up the wheel to one of the crew, and went into the saloon to discuss with Tremayne and Natas the all-important scrap of news that had fallen from the lips of the captain of the British cruiser. What was the other air-ship that had been seen crossing the Mediterranean? Surely it must be one of the Terrorist fleet, for there were no others in existence. And yet strict orders had been given that none of the fleet were to take the air until the _Ithuriel_ returned. Was it possible that there were traitors, even in Aeria, and that the air-ship seen from Larnaka was a deserter going northward to the enemy, the worst enemy of all, the Russians? CHAPTER XXIII. A BATTLE IN THE NIGHT. At half-past five on the morning of the 23rd of June, the Cunard liner _Aurania_ left New York for Queenstown and Liverpool. She was the largest and swiftest passenger steamer afloat, and on her maiden voyage she had lowered the Atlantic record by no less than twelve hours; that is to say, she had performed the journey from Sandy Hook to Queenstown in four days and a half exactly. Her measurement was forty-five thousand tons, and her twin screws, driven by quadruple engines, developing sixty thousand horse-power, forced her through the water at the unparalleled speed of thirty knots, or thirty-four and a half statute miles an hour. Since the outbreak of the war it had been found necessary to take all but the most powerful vessels off the Atlantic route, for, as had long been foreseen, the enemies of the Anglo-German Alliance were making the most determined efforts to cripple the Transatlantic trade of Britain and Germany, and swift, heavily-armed French and Italian cruisers, attended by torpedo-boats and gun-boats, and supported by battle-ships and depôt vessels for coaling purposes, were swarming along the great ocean highway. These, of course, had to be opposed by an equal or greater force of British warships. In fact, the burden of keeping the Atlantic route open fell entirely on Britain, for the German and Austrian fleets had all the work they were capable of doing nearer home in the Baltic and Mediterranean. The terrible mistake that had been made by the House of Lords in negativing the Italian Loan had already become disastrously apparent, for though the Anglo-Teutonic Alliance was putting forth every effort, its available ships were only just sufficient to keep the home waters clear and the ocean routes practically open, even for the fastest steamers.