Some twenty minutes afterwards he was surprised to hear another series of explosions on the road behind him. A little later the wind carried towards him the purr of a motor bicycle. It was rapidly approaching; the crash of bursting shells came nearer and nearer. Was the rider a friend or an enemy? It could not be either Harry or the German he had met, for he had seen at a glance as he passed by that their machines were crippled. He was bound to be discovered; the ditch, while deep enough to conceal him from the gunners in the distance, would not hide him from anyone passing along the road, even if he lay flat in the filthy ooze. He drew the revolver which Captain Adams had lent him, resolving to get his shot in first. Only a few seconds elapsed between his hearing the sound and the appearance of the bicycle round a curve in the road behind. The rider was in khaki; he was flat over the handle-bars; the machine seemed to leap along the road. It flashed by, and Kenneth, crouching over the ditch, was amazed to see that the rider was Harry. Whether his friend had recognised him he could not tell. Quite oblivious of the shells that were still bursting on and near the road, he watched the bicycle’s breakneck career until it passed under a bank that protected it from the German guns, turned a corner, and disappeared. Next moment there was a crash behind him; he was conscious for the fraction of a second of sharp blows on every part of his body; then he knew no more. CHAPTER XV THE OBSERVATION POST Harry reached the divisional headquarters without further mishap, and delivered his despatch. The rider who had come by the long way had not arrived. It was more than half an hour later when he at last rode in, and explained that he had been delayed at several points by congestion of traffic. Meanwhile Harry had obtained leave to ride back and bring in his companion, whom he expected to meet within a mile or two. Evening was coming on; heavy clouds were heaping themselves in the western sky, hastening the dark. Harry had only the vaguest idea of the locality of the spot where he had caught a momentary glimpse of Kenneth, and after riding for some distance, untroubled by attentions from the German gunners, without meeting him, he began to feel uneasy. The sight of the abandoned motor bicycle increased his misgiving. Turning at the bridle path he rode back very slowly, closely scanning both sides of the road. At length he descried, in the failing light, a body lying half in, half out of the ditch. He jumped off his machine and hastened to the prostrate form, dreading to find that his friend was killed. But a moment’s examination sufficed to reassure him. The heart was still beating. A few drops from his flask revived Kenneth, who sat up, a deplorable object, caked with mud from head to foot. "How do you feel, old man?" asked Harry anxiously.