There was the way back, of course; but the desire upon both now was to go forward, for the curiosity which had been growing fast ever since they started was now culminating, and they were eager to penetrate the mystery of the place.
"What are we going to do next ?" said Mike.

"See if we can't get down to the shore, of course;" and Vince seated himself between two rugged, tempest-worn points of rock, and had a long, searching look beyond the edge of the precipice below him.
First he swept the high barrier of detached rock which stretched before him two hundred yards or so distant, and apparently shutting in a nearly circular pool; for he and his companion were at the head of a deep indentation, the stern granite cliffs curving out to right and left, and seeming to touch the rocky barrier, which swarmed with birds on every shelf and ledge, large patches looking perfectly white.
"Seems like a lake," said Mike suddenly, just as Vince was thinking the same thing.
"Yes, but it can't be," said Vince.

"Look down there to the left, how the tide's rushing in.

Looks as if a boat couldn't live in it a moment." "And if the tide rushes in boiling like that, there must be a way out.
Think there's a great hole right through under the island ?" "No; it looks deep and still there at the other end of the rocks, and-- yes, you can see from here if you stand up.

Why, Ladle, old chap, it is running." Vince had risen, taken hold of one of the jagged pieces of rock, stepped on to a point, and was gazing down to his left at the pent-in sea, which was rushing through a narrow opening between two towering rocks, foaming, boiling, and with the waves leaping over each other, as if forced out by some gigantic power, but evidently hidden from the side of the sea by the great barrier stretched before them.
"I can't see anything," said Mike.
"Climb up a bit.