But the light showed them one thing, at least. This was that the two sentries were still sound asleep, doubtless never imagining for a moment that there was the slightest chance of those on board the diving craft receiving help. Indeed, if it had not been for Tom's ingenuity and courage, this would have been the case.
Noiselessly, almost, the two adventurers made for the conning tower. They crept silently along over the deck in their bare feet and gained the helmet-like structure without a hitch occurring.
"Now to open up our prison," whispered Tom, as Mr. Ironsides examined the bolt by which Captain Rangler had imprisoned them.
It was furnished with a lock, but, luckily, Captain Rangler had had no key to fit it. The lock, in fact, was not needed, so long as the inmates of the submarine were within. But now Mr. Ironsides slid back the bolt without difficulty and opened the hatch.
He had just opened it, and was about to step within, when one of the sentries awakened. At the same instant came a flash of lightning. It showed the man two white-clad figures, hovering about the conning tower.
A sudden access of superstitious terror seized him. So far as he knew, there was no possible way of emerging from the conning tower. These two white figures, then, must be beings from another world.
With a wild yell he flung himself into the water, and began swimming with might and main for the tug. His shouts aroused his companion. He, however, was cast in another mold. He realized almost instantly that an escape had been effected in some manner. Raising his rifle, he began firing at the two figures.
Raising his rifle, he began firing at the two figures.