A short distance beyond Dun the German general staff, realizing that the Americans could not be stopped in the village, had hastily thrown up a wandering system of trenches, and to these the enemy now retired. Immediately General Lawrence ordered a halt, that he might better bring his own lines into cohesion. The American and German artillery, hastily rushed up, continued the struggle at long distance. An hour later, Hal, returning toward his own place in the line, accompanied by the marine who had killed the German machine gunner, came abreast of a "baby tank." The tank appeared perfectly intact, but the lad knew at a glance that there was no crew within. "I wonder why?" he muttered, and stopped to investigate. The small door that served as an entrance was open. Hal peered in. The marine who was with him also stopped. "Where's the crew, sir?" he asked. "You know as much about them as I do," was Hal's reply. "Maybe they've gone after 'gas,'" said the marine. Hal climbed in and examined the petrol reservoir. "Plenty of gas," he said. He examined the other mechanism carefully. "Nothing wrong so far as I can see," he declared. "However, it's none of our business. We'll be moving on." But at that moment came from General Lawrence's portion of the field the call for a general advance. Hal glanced around quickly. He was still some distance from his own post, and he saw his men start forward under command of Lieutenant Edgerton. It was unlikely that he would be able to overtake them. He turned to the marine. "What's your name?" he demanded. "Bowers, sir." "All right. Bowers. Do you know anything about these tanks?" "Not much, sir. I can drive an automobile or an airplane, and I've watched these things work. Guess I could run one if I had to." "Well, you can work the gun, can't you?" Hal wanted to know. "You bet I can, sir, and I'll guarantee not to miss very often. Are you thinking of boarding this craft, sir?" "I am," said Hal. "We seem to be out of the fight right now. It's up to us to get into it again. Climb in, man." Bowers boarded the tank with alacrity and deposited himself beside the single machine gun. Hal perched himself in the pilot's seat and opened the throttle. The tank moved forward. In the distance, both to right and left, Hal saw other tanks waddling forward. They were all still too far from the enemy to do any great damage, but they were ambling forward as swiftly as their peculiar construction would permit, all anxious to approach within striking distance. In front, the American infantry, with absolute disregard for the German artillery bombardment, dashed for the enemy trenches. They climbed in, and even from where Hal was the lad could see the signs of terrible combat within.