"Right you are," said Oscar, "and the sooner the better. That cliff may be coming down on our heads."
The order was given to go forward, but the new Holland had run less than a hundred feet when she came to a sudden stop.
Rocks blocked her way on every side.
Then the submarine craft began to back, but soon other rocks brought her to a standstill.
The terrible truth burst upon those on board.
They were prisoners in the cave under the ocean!
CHAPTER XXI.
OUT OF ONE DANGER INTO ANOTHER.
Entombed alive!
Such was the agonizing thought which came to the mind of everybody on board of the Holland XI.