e
through which they must have come overnight, but he could never be in
the least sure; and as they went on, he had to content himself with
looking up at the ridge which faced the caverns, and beyond which they
believed the sea to be.

Everywhere at the foot of the cliffs the water was deep, and so clear
that they could see the rocks at the bottom, smooth, and
treacherous-looking, apparently rising up to capsize the boat; but they
glided over all in safety, the great basin being worn smooth by the
constant friction of the currents, and at last began to approach the end
opposite to where they had been deftly taken out by the men.

Here they looked eagerly for another way of getting out--the rift
through which the waters must pass back into the sea--but, if it
existed, it was shut from their sight by the heaped-up rocks, and the
current carried them on and on with unchecked speed.

"No wonder I thought we were a long while getting out to sea!" said
Vince at last: "we can't have gone near the big channel through which
the lugger must come and go."

"Never mind that," said Mike impatiently; "there must be another way out
from this basin. We saw signs of it from up above, when you sat up
there and I held the rope."

"Yes," said Vince gloomily; "but sitting up there's one thing, and
sitting down here's another. Think we shall find another way out this
end? Must, mustn't we?"

Mike nodded as he stood up and searched the rocks for the opening that
was hidden from their eyes, from the fact that it was behind one of the
barriers of rock and far below the surface current which swept them
along.

As far as they could judge, they were going on for half an hour, making
the complete circuit of the great watery amphitheatre; and then, as they
passed the caverns again, they determined to examine the other end more
carefully, for the exit used by the smugglers, which must, they knew, be
ample and easy if they could master the knack of getting the boat in.
For they had some hazy notion of learning how it was done and then
hiding till night, when they might manage perhaps to pass out unseen.

"But if we did," said Mike despondently, "we should perhaps be swept in
here again, or be upset and drowned. I say, Cinder, did you ever see
such an unlucky pair as we are?"

"Never looked," said Vince; "but I tell you what: we shall have to land
in the big cave, and get through to ours."

"What for?"

"Breakfast. There's all our f