"All right," consented the boy, starting forward. "But remember," he cautioned, "we shall not relish anything in the way of tricks."
"Suspicious still, I see," laughed the other. "Well, follow this light, and be careful how you step. There may be irregularities in the floor that you'll have to discover for yourselves. It won't be safe to do any talking for a while. The Germans are watchful."
The three boys were startled to observe a circle of light appear upon the stone floor of the apartment at some little distance from the spot where they were standing. It appeared to emanate from an electric searchlight held in the hands of the stranger.
Ned took a step toward the light. Jack and Harry did likewise. Their surprise increased as they observed that the light moved along the floor at a pace about equal to their own.
Ned thought that he could faintly discern the feet of the person carrying the light, but was unable to learn anything of the character of the person. He was torn between his desire to escape from the apartment and the wish to learn the identity of the stranger.
Only a few steps had been taken by the stranger before the light was extinguished. Instantly the three boys halted.
"S-s-sh!" came a warning hiss. "Be mighty careful now of your conversation and your footsteps. Keep as quiet as possible and follow me closely. We are all in extreme danger!"
In spite of his efforts at self-control, Ned's muscles trembled and he found it difficult to walk steadily. Assuming that his chums were in like plight, the lad summoned all his courage and reached out a reassuring hand to the others. The contact with his friends seemed to restore the equilibrium that had been Ned's most valuable asset in times of stress and danger in his many adventures.
Long afterwards the boy declared that in all his experiences that compassed many strange and hazardous enterprises in the United States, Canada, Mexico, the Philippines, China and other countries he had never felt so keenly the need of aid as he did at that moment.
Not for long, however, were the boys permitted to consider the peril of their position. Almost instantly they heard a faint grating sound directly in front of them. A cold draught of damp, musty air struck their faces, and they understood that a door had been opened into some other apartment. The odor of the incoming air told them plainly that the next apartment was also underground, and they surmised that it had not recently been occupied.