"Whack her up for all she's worth," ordered Ralph, addressing the motor mechanic. "Now, lads, it's a race. It's up to us to get to that viaduct before the train can cross." The bridge, although not marked on Ralph's military map, was in the position indicated by the impersonator of Captain Cludderborough. It crossed a small stream at a point one hundred yards or thereabouts to the north of the original structure that had been bombed and demolished by British airmen. The temporary viaduct was made of huge baulks of timber supporting a central span of only thirty feet. The banks of the stream that flowed underneath were low, the ground sloping gently on the near side but rising with considerable abruptness on the remote side. With a succession of jolts and bumps the Tank plunged downhill at a greater rate than she had ever done before in her brief yet strenuously exciting career; but notwithstanding the hot pace Setley was forced to come to the conclusion that the troop train would be the first to reach the bridge. He thought hard. The time for decisive action, bordering on self-sacrifice, was at hand. Unable to destroy the bridge before the train rumbled across he decided to try conclusions with the locomotive. "Pass the word that any man who wishes may get out," he said to Sergeant Alderhame. "I'm going to ram that engine." Alderhame bellowed out his superior officer's permission. It would be a comparatively easy matter for the men to alight from the moving Tank, but one and all elected to take their chances with their youthful officer. Gripping the nearest object that formed a likely hold the men awaited with grim faces and tightly closed lips the impact with an equal target of metal moving at five or six times the rate of the landship. The driver of the locomotive had spotted the Tank. To Ralph's satisfaction he saw that the German was applying his brakes and shutting off steam. Had he maintained his speed there was a chance that he might have escaped a collision. By easing down he not only played into the hands of his enemy but mitigated the chance of the Tank's destruction. Had there been time Ralph would have merely steered his Tank across the lines, in which case the weight of the landship would have twisted the track and caused the train to leave the metals. But there was not. To attempt to do so would result in the engine striking the Tank fairly on her side. Meeting at an aggregate rate of nearly thirty miles an hour the Tank's nose struck the locomotive a glancing blow somewhere in the region of the driver's cab. With a terrific rending of metal and the hiss of escaping steam the engine toppled over on its side, while the carriages either telescoped or lurched over the slight embankment. As for the Tank, she began to climb upon the wreckage of the vanquished; then turning began to describe a small circle.