They all went to the place where the passage branched off. They squeezed down it till they came to the block. George pulled away some of the stones and tried to see how much of the passage was stopped up.

“I believe if the four of us could work at it we might clear it in time,” said George at last. “And I’ve got a good idea too - the block is mostly of stones and bits of rock. If I pick them up, pass them to Jack, and he passes them to Paul and Paul to Mike, Mike could pile them up behind him and make them look as if there has been a good old roof-fall there! So if Mr. Diaz does come along he’ll think it’s impossible to come this way. And we’ll be safely on the other side of the stones!”

“Good old George!” said Mike and Jack, who always loved a good idea. “Come on - we’ll start.”

“What do I do?” asked Paul, who was half-frightened, half-thrilled at being with the others. They told him what to do.

“You only just take hold of the stones I pass you,” said Jack, “and pass them behind to Mike.”

They set to work. George cleared away the stones, passing them to the others. Mike threw them behind him, and soon a great pile lay there, looking exactly as if they had fallen from the roof of the passage!

Soon George had cleared away quite a bit of the block. He shone his torch up and down it, and gave a cry of joy.

“I believe it’ll be all right, boys! I can see the passage beyond already. We’ll only need to clear a bit more, and we shall have a hole big enough to squeeze through.”

They worked and worked. Paul became tired and they had to let him have a rest. Two hours went by. George felt rather anxious. He did not want Mr. Diaz to discover that Paul and Mike had escaped before they had all got safely away in the boat.

At last there was a hole big enough to squeeze through. One by one they got through it, and then George did a funny thing.