With a dull thud Hamerton alighted on his hunched shoulders. Instinctively he kept his head well under, and this saved him a broken neck. Inertly he rolled over on his side, wondering where he was and how far he had fallen. Nor could he help expecting to see the soldiers from the hut, who must have heard the noise of his fall.
A minute or so went by. No curious soldier appeared on the edge of the pit or whatever it was. He began to consider how he could escape.
"Solid steel, by Jove!" he exclaimed softly, tapping the substance on which he had fallen. He stood up. He found himself in a circular hollow surrounded by a wall less than six feet in height. The metal floor was perhaps thirty feet in diameter and slightly domed.
"Looks like the top of a gasometer or an oil-fuel tank," mused Hamerton. "I may as well have a short investigation. Can't stop long, or Detroit will be blundering in on top of me. Ah! What's this?"
His foot encountered a raised object. It was an armoured slide of some sort. He tried to raise it, but in vain. Then he applied pressure in a horizontal direction. This resulted in the metal slab sliding and disclosing a pitch-dark cavity.
"Wish I had a match," he muttered. "Well, here goes! I've been in worse holes than this."
His feet encountered the rungs of a ladder. Three downward steps did he take, then there was a sharp metallic click, followed by a sudden blaze of light.
CHAPTER XV
Recaptured
Fully expecting to be challenged and seized by an unseen foe, Hamerton grasped the metal slide with the intention of making a dash for liberty. As he did so the cover slipped on its groove and closed the aperture, jamming the Sub's fingers as it did so.