Without immediately answering, Colston put his arm through his, drew him away from the men who were standing about, and told him as briefly and gently as he could the terrible news of the calamity that had befallen the Brotherhood, and the errand upon which he had come. Arnold received the blow as a brave man should--in silence. His now bronzed face turned pale, his brows contracted, and his teeth clenched till Colston could hear them gritting upon each other. Then a great wave of agony swept over his soul as a picture too horrible for contemplation rose before his eyes, and after that came calm, the calm of rapid thought and desperate resolve. He remembered the words that Natasha had used in a letter that she had given him when she took leave of him in Russia. "We shall trust to you to rescue us, and, if that is no longer possible, to avenge us." Yes, and now the time had come to justify that trust and prove his own devotion. It should be proved to the letter, and if there was cause for vengeance, the proof should be written in blood and flame over all the wide dominions of the Tsar. Grief might come after, when there was time for it; but this was the hour of action, and a strange savage joy seemed to come with the knowledge that the safety of the woman he loved now depended mainly upon his own skill and daring. Colston respected his silence, and waited until he spoke. When he did he was astonished at the difference that those few minutes had made in the young engineer. The dreamer and the enthusiast had become the man of action, prompt, stern, and decided. Colston had never before heard from his lips the voice in which he at length said to him-- "Where is this place? How far is it as the crow flies from here?" "At a rough guess I should say about two thousand two hundred miles, almost due east, and rather less than two hundred miles on the other side of the Ourals." "Good! That will be twenty hours' flight for us, or less if this south-west wind holds good." "What!" exclaimed Colston. "Twenty hours, did you say? You must surely be making some mistake. Don't you mean forty hours? Think of the enormous distance. Why, even then we should have to travel over sixty miles an hour through the air." "My dear fellow, I don't make mistakes where figures are concerned. The paradox of aërial navigation is 'the greater the speed the less the resistance.' "In virtue of that paradox I am able to tell you that the speed of the _Ariel_ in moderate weather is a hundred and twenty miles an hour, and a hundred and twenty into two thousand two hundred goes eighteen times and one-third. This is Wednesday, and we have to be on the Asiatic frontier at daybreak on Friday. We shall start at dusk to-night, and you shall see to-morrow's sun set over the Ourals." "That means from the eastern side of the range!"