As a matter of fact, it was a mounting conviction that he was not the only one who was hiding in the darkness and watching Number One Fifty-Six that caused him to stay where he was. No proof. Nothing tangible. It was just that a few times he would have sworn that he saw shadowy movement across the street. Maybe it had been his imagination, the strain on his eyes. But maybe not. It was almost as though he could actually feel somebody over there on the opposite side of the street. And so he remained hidden and watching as another hour dragged itself off into the eternity of forgotten time. But by the end of that hour he had reached the limit of his endurance. Gestapo agents or no Gestapo agents, he just had to go over there across the street and find out for sure if Number One Fifty-Six was occupied or not. If it wasn't occupied, then-- He gave a little shake of his head in the darkness and wouldn't let himself complete the rest of the sentence. "It's my only hope!" he whispered fiercely to himself. "As things are now, I'm right up against a brick wall. Weiden's _got_ to be living there, and _I've_ got to contact him. He's the only one who can possibly help me now. Come on, Lady Luck, give us another little break, please." For a moment he bowed his head as though in prayer, and then, silent as the very darkness of night itself, he moved out of his place of hiding and started across the street to the other side. When but halfway across the street he heard a faint sound ahead of him that made his heart stop beating, and his hair practically stand up on end. It was just a sound, one of a million different kinds of sounds that anybody might have heard. Maybe it was a door closing, or someone taking a step, or knocking against something accidentally in the dark. The sound had come and gone before he could even begin to figure what it might have been. But as he froze motionless in the street, with his service Luger clutched tightly in his free hand, he was convinced beyond all doubt that the sound had been made by a human being. There were no stray dogs or cats in Duisburg to go around nights making sounds. They had long since disappeared, and no doubt more than one German housewife, who had stood in front of the butcher shop all day only to learn that there wasn't a scrap of meat left, could tell where those stray dogs and cats had "gone"! No, the sound had been made by a human form, a human being. And in a crazy sort of way Dawson expected to see the night spurt flame, and to hear the bark of a gun in his ears, expected his body to feel the sting of a bullet from the gun of some Gestapo killer who had mistaken him for one Heinrich Weiden. It was perhaps a completely mad thought, but in that instant Dawson experienced more cold fear than he had in all his life before.