It appeared ghostly in the dark, the big steel girders taking on weird and fantastic shapes. A train rushed across its span, roaring and throwing a shower of sparks high into the air. "Come on," urged Hugh and scrambled up the embankment. Bob followed close at his heels and together they made their way towards the bridge itself. They soon found themselves picking their way on the open ties above the water; as they were headed west they of course took the east-bound track. The walking was precarious and they had to pay close attention to what they were doing, for a misstep might prove fatal. Suddenly a sharp command to halt startled the two boys. They stopped short and peered intently about them in the dark. "Who are you?" demanded a curt voice, and Hugh and Bob saw the figure of a man in khaki outlined against the skyline. A faint flicker of light showed a keen-edged bayonet affixed to the gun he carried. "Who are you!" repeated the voice, strangely familiar in tone to both of the boys. "Come over here, and keep your hands over your head." "Harold!" exclaimed Bob suddenly. "Is that you?" "That you, Bob?" queried Harold, for the guard proved to be Bob's older brother. "Who's that with you?" "Hugh." "Well, it seems to me you two are pretty nervy," said Harold testily. "What are you doing down around here anyway?" "We were going down to Brown's boathouse to see Hugh's canoe," Bob explained. "We thought we'd take the short cut over the bridge." "And stand a good chance of getting shot," said Harold. "All bridges are guarded by soldiers with rifles, and we're not supposed to wait forever before we shoot either." Hugh and Bob had advanced to the spot where Harold was standing, and the three young men were grouped in a small circle. "We never thought of that," said Bob sheepishly. "Don't you know the United States is at war?" "Of course we do." "Well, then--. Sssh!" hissed Harold suddenly. He peered intently down the railroad track. The figure of a man could be seen approaching. "Get back, quickly," whispered Harold, and the two boys flattened themselves against one of the big steel girders. Nearer and nearer came the man. Harold stood motionless, his gun half raised and ready for instant action. Hugh and Bob looked on, fascinated. When about thirty yards distant the man stooped and appeared to be fumbling with something at his feet. Only for a moment, however, for he soon straightened up again and proceeded on his way. "Halt!" commanded Harold sharply. The man started, and then came to an abrupt stop. "Come over here," Harold ordered. His order was obeyed somewhat slowly, but without question. "What's your name?" queried Harold, as the man came up to him. There was no answer. "What's your name?" repeated Harold shortly. "John Moffett," said the man sullenly. "Where do you live?" "High Ridge." "Where in High Ridge?" "Elm Street." "What number?" "Twelve eighty-two," said the man after a moment's hesitation.