Everything was quiet as regards the criminal business for the next two days, as Penn made no attempt to punish Dan for the fright he had given him. Halliday himself was much too eager over the race to trouble about the matter, but he kept a sharp eye on the Vincent machine, still stored at Blackheath, so as to guard against any tampering. The start was to take place at Blackheath, and on the appointed day five competitors were on the spot surrounded by a large crowd of curious people anxious to witness the conquest of the air. Amongst those present was Durwin, who pushed his way to where Dan was looking over his aeroplane. The aviator did not see the lean, keen-eyed man until he was touched on the elbow. "Is it all right, Halliday?" asked Durwin, nodding toward the machine. "Perfect. She's a beauty, and it won't be her fault if I don't lift York Minster before sunset. What are you doing here, Mr. Durwin? I didn't know that you took an interest in aviation." "I take an interest in this search for Moon's assassin," said Durwin drily, but in low tones. "Laurance saw me and related your discovery. I am looking about for Marcus Penn and intend to ask him questions." "He may be on the ground," said Dan, glancing around, "since Lord Curberry's place is a stone-throw away. But he won't speak." "I'll make him speak," said Durwin with a grim look. "Well, I hope you'll win, Halliday. When you return to town look me up. I may have something to tell you," and he moved away with a significant look. Dan could not leave his machine, or he would have followed, as there were several questions which he greatly desired to ask. The day was cold and dry, with few clouds, and a good deal of sunshine, so the conditions for the race were fairly good. The wind was rather high, and that vexed the aviators, as the art of flying is not yet so perfect as to control the winds when they are over-strong. However, to go against these strong air-currents would be an excellent test of the qualities of the various machines. The start was to take place at one o'clock, and the competitors hoped to reach their destination before five o'clock. Some of the aeroplanes could travel at forty miles an hour; others at fifty, but so far as Dan knew, his was the sole machine which could gather sixty-miles-an-hour speed. If Vincent could be believed, the aeroplane ought to travel the hundred and eighty-odd miles, if the conditions were tolerably good, in a trifle over three hours. Dan, now having perfect mastery of the biplane, hoped to accomplish the wonderful journey in a shorter space of time. But this hope had yet to be verified. Meanwhile, having seen that all was in order, he turned to speak to Lillian who had just come up accompanied by Mrs. Bolstreath. Lord Curberry was in attendance, and in the distance Dan caught a glimpse of the yellow-faced secretary, looking unhappy and nervous.