After a while Mr. Greenwood raised himself. Grimly he reflected that his visit to Auldhaig had not been uneventful. Adventures were crowding upon each other's heels. His zest for excitement was increasing.
The bush had broken his fall. He found himself on a flat floor of what appeared to be a cavern. Where the foliage had been, appeared an irregular opening through which the dim twilight filtered without sufficient intensity to reveal his surroundings.
"One thing, I've a roof over my head," he soliloquised. "Now I am getting on. But I really cannot understand this peculiar odour. It reminds me very forcibly of a garage. Yes, petrol fumes. To be on the safe side I don't think I'll smoke just at present. In fact, I think it would be well to investigate."
Cautiously and on all-fours Mr. Greenwood commenced his tour of discovery, crawling lest there should be a hole in the floor.
Soon his head came in contact with a metallic object. It was a filled petrol tin, one of dozens, possibly hundreds, stacked in orderly manner against one wall of the cave.
"Now, that's strange," murmured Mr. Greenwood "It is pretty certain that that lot would not have been brought into this place from the cliff, so there must be an outlet besides the hole through which I tumbled. Why should a place like this be chosen to store petrol? And why was the hole so carefully hidden with a dead bush? It looks jolly fishy. Of course I've heard plenty of talk of German secret petrol-bases in Great Britain, but I never believed the tales. By smoke! I fancy I've stumbled upon one now. The first question is, how am I to find a way out without being seen?"
Resuming his cautious crawl, Mr. Greenwood penetrated into the recesses of the cave, keeping within touch of the rows of petrol-cans on his right. Contrary to his expectations, the floor was smooth, though tending to rise in the direction in which he was proceeding.
At about twenty yards from the hole through which he had tumbled, he remembered that he had left his tracks uncovered. No need to creep on all-fours now, for he had the irregular patch of light to guide him. Grasping the displaced bush, he replaced it in the opening, and chuckling to himself he again resumed his tour of exploration.
His spirits were rising rapidly. The love of adventure, that had lain dormant for years, was reasserting itself. Also he began to realise that he had now a chance of doing something definite for his country—a chance that hitherto had been denied him on account of his age.
He had quite forgotten the derelict mine. The fears that he had entertained on that score had been completely dispelled by the thought that he had lighted upon a discovery of real national importance—the existence of a secret base for hostile submarines.