“Go ahead,” countermanded Wilson after a quick glance. “It’s a tunnel. There’s nothing to do but keep on. It kills our chance of getting to the shore. But on the other hand it’s dark in there and we may be able to double on these fellows and give them the slip. Keep on.” The boat shot quickly into the blackness of the tunnel through which the canal flowed at that point. The bullets ceased to sing about them. The radiance of the star shells died away. Darkness enfolded them, a darkness so intense that they were absolutely hidden from each other. They rowed along for some distance with undiminished speed. Then as no sound of oars was heard in pursuit, the corporal gave the word to lay on the oars. “Some race!” panted Frank as he wiped the perspiration from his forehead. “But we beat them to it!” gasped Tom. “Gee, I never worked so hard in my life!” “They don’t seem to be following us,” commented Billy. The corporal pulled out his flashlight and turned it around them. They were startled to see how the stream had narrowed after entering the tunnel. There was barely room for two barges to pass each other. The corporal’s face was grave as he made the discovery. “No chance of doubling on them in here,” he remarked. “Looks very much as if they’d got us in a trap. If they follow us up, we’ll have to fight it out. And we haven’t got too much ammunition left. I sent most of my bullets at the Huns in the boats.” “You toppled over two of them,” said Tom. “I saw them drop. But there’s a lot of them left.” “There’s a light at the mouth of the tunnel!” exclaimed Billy. They looked back. From the point that they had reached the tunnel extended back to its mouth as straight as an arrow, and they could see the two boats that had been in pursuit lying beside each other, while from the light of a lantern in the bow of one they could see the figures of the men engaged in an animated debate. They seemed to be divided as to the course to pursue. “Wonder if they’ll follow us in,” murmured Tom. “They don’t seem to relish the idea very much,” remarked Frank. “The chances are that they will,” judged the corporal. “They know that they outnumber us, and they won’t want to let us go back to our lines with the information we’ve picked up.” Suddenly the light went out. “I wonder what that means,” said Billy anxiously. “I think it means they’re coming,” replied the corporal. “They put the light out so that they won’t offer a mark for our revolvers. It looks as though it might come to a battle in the dark.” “If it does, I’ll match our eyes against theirs,” remarked Frank confidently.