Bob's opportunity of escape seemed to him afterwards almost like a miracle. One night, as chance would have it, only one of the guards was on duty, and he determined to take advantage of the circumstance. If he were to escape, a bold, almost mad, endeavour must be made. Failure would mean death; but, with all the enthusiasm of youth, he decided to risk it. The guard was a man about his own height and build, and, under ordinary circumstances, would be his match in physical strength. Of course a hand-to-hand struggle was out of the question; a cry from the German soldier would mean arousing hundreds of others, and then Bob's fate would be sealed. But if----and his brain almost reeled at the madness of the plan which had been so suddenly born in his mind. Seizing his opportunity, and taking full advantage of the fact that he had been allowed the use of his limbs, he suddenly struck his guard a heavy blow, which, for the time, stunned him; then, seizing the man's rifle, he struck him a blow on the head which left him senseless. Quick as lightning, he pulled the man's clothes from off his prostrate body, and a minute later he was himself, to all appearances, a German soldier. As he reflected afterwards, the thing happened so quickly and under such strange circumstances, that it seemed to him impossible. To overpower a German guard in the midst of thousands of German soldiers, and then to appear among the others in a German uniform, seemed absolutely impossible; yet he did it. It was for him, now, to find his way through the German lines without revealing his identity. One thing was in his favour--that was a fact which he had kept rigorously secret--he spoke German almost like a German. I will not weary the reader with Bob's experiences during the next few hours. In the letter he wrote to me about them, he gave but few details. Nevertheless, he told me enough to make me realise that for hours he was within an ace of detection and death. All around him shot and shell were falling, for although night had come, a continuous bombardment was taking place. Each army was sending forth its missiles of death; the guns of each were pounding to the other's trenches. Before daylight came Bob had, in the darkness, passed the advance lines of the enemy, and was making his way towards his own people. But even yet his danger was not at an end; indeed, he was in more immediate peril than when he was a prisoner in the German camp. Clad as he was in the enemies' uniform, he knew that at first sight he would be shot down. Still he must take his risk and press forward. Moreover, he knew that anything like hesitation must end in disaster.