Madden's mind attacked more violently than ever the incomprehensible motives behind this inscrutable mystery. What was the key to this incredible affair? In the midst of his mental struggle, he felt a hand on his arm, Caradoc said in his ear,
"What do you say we get in the small boat and pay them a visit?"
"It's a big risk. I daresay we'll get our heads blown off."
"I had thought of that," agreed Caradoc.
"Come on," said the American, and the two moved across the deck to see if they could still use the dinghy, which had been trailing along all this time.
Nearly an hour later, the two boys in the dinghy approached the puzzling craft with muffled oars. As Madden and Caradoc drew near, the vast size of the strange ship grew more striking. The faint impression of light which they had first received grew stronger and Madden saw that the decks were illuminated by long bands of diffused light, although he could not guess its origin.
On the lowest deck, the American made out the small figure of a man marching back and forth with a gun.
At this sight, both boys stopped rowing, lifted the oars from tholes and began paddling noiselessly, canoe-fashion.
"That must be the accommodation ladder," whispered Madden, "where the guard is."
"Who are they afraid will board them?" queried Caradoc. "Mermaids?"