"But they never brought any of the treasure to land."
"No—at least, none that was reported. They might have done such a thing in secret."
"Supposing we move the bell around and make another search," suggested Dave. "The demons appear to have vanished."
They pumped in a fresh supply of air and then moved around in a large circle.
It was hard work, and the confinement of the diving bell gave each a headache and a strange ringing in the ears.
Presently they came to a curiously shaped mound of shells, covered with moss.
"Hullo, what's this?" said Dave. "Hang me if it doesn't look like the home of some submarine animal. Perhaps it's a meeting house for those demons."
"If it is, we had better move on," replied Amos Fearless, in the sign language.
But Dave was curious to investigate, and presently they replaced their helmets, took in some fresh air, and sallied forth to examine the mound.
Inside all was damp—a dampness different from that produced by the water around them.