"I'll say Tom is being careful," thought Ned, as he stepped out through the runway toward the erection shed.
Before he reached the entrance to the huge shed, however, Ned chanced to look down the enclosure. There were several arc lights burning, but even these only furnished a dim illumination for the whole yard.
He supposed that four watchmen were tramping their several beats along the inside of the stockade and close to the trolley-track. But when he saw an instant gleam of light down there, close to the ground, Ned did not believe that it was the flash of a torch in the hand of any sentry.
"Funny," he muttered. "That's outside the fence, or I'm much mistaken. I wonder now—"
He turned from the door of the shed, left the runway, and began walking toward the distant point at which he had seen the mysterious flash of light.
Chapter XV
The Enemy Still Active
Ned was dressed in a dark business suit, so he was not likely to be observed from a distance, for it was a starless night. Half way to the end of the great yard he began to wonder if the light he had seen might not have been an hallucination.
He doubted very much if anybody was creeping about outside the fence. The boards were close together, with scarcely a crack half an inch wide anywhere. A light out there—