“Professor Challenger,” said he, in a solemn voice, “I owe you an apology. Sir, I hope that you will forget what is past.”

The two men for the first time shook hands. We have gained so much by this clear vision of our first pterodactyl! It was worth a stolen supper to bring two such men together.

But if prehistoric life existed on the plateau it was not in abundance, for we didn’t see any other prehistoric animals during the next three days. We continued to walk around the cliffs. However, in no place did we find any point where they could be ascended.

On the sixth day we completed our first circuit of the cliffs, and found ourselves back at the first camp, beside the isolated rock.

What were we to do now? Our stores of provisions, supplemented by our guns, were holding out well, but the day must come when they would need replenishment. In a couple of months the rains might be expected, and we should be washed out of our camp. No wonder that we looked gloomily at each other that night.

But it was a very different Challenger who greeted us in the morning… a Challenger with contentment and self-congratulation shining from his whole person.

“Eureka!” he cried, his teeth shining through his beard. “Gentlemen, you may congratulate me and we may congratulate each other. The problem is solved.”

And he pointed to the spire-like pinnacle upon our right.

We know that it could be climbed. But a horrible gap lay between it and the plateau.

“We can never get across,” I gasped.

“We can at least all reach the summit,” said he. “When we are up I may be able to show you that the resources of an inventive mind are not yet exhausted.”

After breakfast our leader unpacked his climbing accessories. John was an experienced mountaineer, and Summerlee had done some climbing at various times. And my strength and activity may have made up for my lack of experience.

It was not a very difficult task, although there were moments which made my hair move upon my head. When we found ourselves on the small platform, some twenty-five feet each way, which formed the summit, we saw a great view. The whole Brazilian plain seemed to lie beneath us. I could see the yellow and green mass of bamboos through which we had passed; and then, gradually, the vegetation increased until it formed the huge forest which extended as far as the eyes could reach, and for a good two thousand miles beyond.

I placed one arm round the trunk of the tree and saw the small dark figures of our servants, looking up at us.

“This is indeed curious,” said the creaking voice of Professor Summerlee.

I turned, and found that he was examining with great interest the tree to which I clung. That smooth bark and those small, ribbed leaves seemed familiar to my eyes. “It’s a beech!” I cried.

“Exactly,” said Summerlee.

“And this tree will be our saviour,” said Challenger.

“My God!” cried Lord John, “a bridge!”

“Exactly, my friends, a bridge! There is always a way out.”

It was certainly a brilliant idea. The tree was a good sixty feet in height, and if it only fell the right way it would easily cross the chasm. Challenger handed the axe to me.

So under his direction I cut such gashes in the sides of the trees as would ensure that it should fall as we desired. It had already a strong, natural tilt in the direction of the plateau, so that the matter was not difficult. In a little over an hour there was a loud crack and the tree crashed over, for one terrible second we all thought it was over. But it balanced itself, a few inches from the edge, and there was our bridge to the unknown.