"Great Scott!" murmured Burton. Dropping the empty tin, he hastened to the aviatik for another. "I say, Dick, do you recognise that fellow?" he asked. "Christopoulos!" Hunter whispered. "As large as life! What on earth are we to do? He will recognise us directly, even if he hasn’t done so already." "Shoot him and scoot!" "I haven’t enough petrol yet. The tank still leaks, though not so badly, and if we shoot, the Turks will swarm up before I can fill up and get away. I think I had better go on with the job, let him come up, and trust to luck." Keeping his back to the pseudo-Greek, Burton carried another tin to the seaplane. Before he had emptied it into the tank the spy came within hailing distance and let out a jovial greeting in German. No doubt he had recognised the German airman’s cap, and, without misgiving, hailed his supposed compatriot. "Good-morning, my friend," he shouted. "I congratulate you. Another German victory!" Burton, his back still towards the spy, finished pouring out the petrol, and placed the tin on the ground. As he straightened himself he discreetly drew his revolver and suddenly turned round. The spy was now within half a dozen paces of him. "Thank you, Mr. Christopoulos," he said. "Another victory--but not a German victory. We shall presently see who is to be congratulated. Meanwhile, you will dismount." The German, who had reined up at the first glance at Burton’s face, turned a sickly colour and half-opened his mouth as if to shout. "Silence!" cried Burton peremptorily. "If you make the slightest sound I will shoot you on the spot." He held his revolver carelessly in his left hand, not pointing it at the German lest any of the Turks should come within view. The spy showed more alacrity than skill in dismounting. He clumsily clambered from his saddle, without daring to turn his head in the direction of the Turks, who could now be heard calling to one another beyond the knoll. Burton went up to him. [Illustration: NONPLUSSED] "Hand over your revolver," he said. "I haven’t got----" the spy was beginning. Burton cut him short. "No nonsense! Hand it over. Quick. At the word ’three’ I fire. One--two----" With an agonised look the German made a dive for his revolver. Burton took it with his right hand before it was released from the spy’s tight pocket. From a distance they might have appeared to be shaking hands. Burton had been rapidly casting about for a means of disposing of the German. He could not shoot him in cold blood; there might perhaps be time to tie him up, but he would then still be able to convey to the Turkish headquarters the information he had gathered at Tenedos. That must certainly be prevented. There was only one thing to be done: they must take him with them. Just as Burton had reached this conclusion, a Turk appeared on the knoll. "Come with me," said Burton sternly.