By supper time, I had finally realized how serious our situation was.
“We have to ration our food,” I said.
My uncle looked at me calmly.
“How long will our supplies last?”
“Three days at most.”
That was bad enough. But there was something far worse.
We were now traveling through what geologists call the transition rocks. There was almost no chance of finding water here.
I had read about the terrible effects of thirst. I knew that if we were forced to go without water for long, our journey—and our lives—could end very quickly.
But talking to my uncle about it was useless. Whenever I raised a serious problem, he always answered with some quotation or philosophical idea.
The next day we continued through the endless underground passage.
Arch after arch.
Tunnel after tunnel.
We walked for hours without saying a word.
Even we had become as quiet as Hans.
The passage no longer seemed to rise. If it did, the slope was so slight that we could hardly notice it.
At times, however, I was certain that we were going downward.
That did not comfort my uncle at all.
The rocks around us were still the same, and the layers of transition rock were becoming more obvious.
Yet the walls were beautiful.
The electric light revealed countless sparkling crystals in the limestone and red sandstone. For a moment, it looked as though we were walking through one of the deep rock cuts in Devonshire.
Huge pieces of marble projected from the walls.
Some were gray like agate, crossed with white veins.
Others were yellow, covered with red markings.
Farther along, we found marble with bright cherry-colored veins running through it.
But the most fascinating thing was that many of these rocks contained the marks of ancient animals.
Nature seemed to be moving forward through time.
Earlier, we had seen primitive trilobites. Now we were finding the remains of more advanced creatures.
Among them were ancient fish whose bodies showed what geologists believed was an early stage in the development of reptiles.
Millions upon millions of these creatures had once lived in the Devonian seas. When they died, their remains became buried in the rocks.
It was obvious to me that we were moving upward through the history of animal life, toward the age when man would eventually appear.
My uncle seemed completely unconcerned.
He was determined to continue, no matter what happened.
I could only imagine that he was expecting one of two things.
Either a deep vertical shaft would suddenly open beneath our feet and allow us to continue downward, or we would eventually meet an obstacle that would force us to turn back.
But evening came.
Neither happened.
On Friday morning, after another miserable night, I woke with a terrible thirst.
My appetite was disappearing too.
Still, we continued.
The three of us followed the endless twists and turns of the tunnel.
Sometimes we climbed.
Sometimes we descended.
Nobody spoke.
Everyone looked tired and gloomy.
Even my uncle seemed to realize that he might have pushed us too far.
After about ten more hours of this slow and monotonous journey, I noticed something strange.
The light from our lamps was no longer reflecting brightly from the walls.
The marble had disappeared.
So had the schist, limestone, and red sandstone.
In their place stood dark, dull walls that seemed to absorb the light.
The passage became extremely narrow.
I placed my left hand against the wall to steady myself.
A moment later, I pulled it away.
My hand was completely black.
I stared at it.
“We’ve reached the coal layers!” I cried.
“A coal mine without miners,” my uncle replied sharply.
“How do you know there were never any miners here?”
“Because I know,” he said in his usual confident, scientific tone. “This passage cuts through layer after layer of coal, but it was certainly not made by human hands.”
He paused.
“Whether nature made it or something else did is not important right now. It is time for supper.”
Hans began preparing our food.
But I could hardly eat.
All I could think about was water.
The little amount we had left was divided among the three of us.
Hans’s flask was not even half full.
That was all the water we had.
My two companions finished their meal and then lay down on their blankets.
They soon fell asleep.
Sleep gave them a temporary escape from their exhaustion and suffering.
But I could not sleep.
I lay awake, staring into the darkness and waiting for morning.
At six o’clock on Saturday morning, we started moving again.
Twenty minutes later, we suddenly entered an enormous underground chamber.
I immediately understood that no human being could have created this place.
If miners had dug such a huge space, the ceiling would have collapsed long ago.
Yet somehow it remained standing, held together by forces of nature.
The cavern was nearly a hundred feet wide and about a hundred and fifty feet high.
It looked as if some enormous underground force had torn the earth apart.
A violent movement deep beneath the surface must have split the rock in two, creating this gigantic opening.
We had entered it for the first time in human history.
The dark walls told the entire story of the ancient coal age.
A geologist could have studied them for years and followed every stage of their formation.
Layers of coal were separated by sandstone and hard clay, which looked as though they had been crushed under an enormous weight.
I began thinking about the ancient world.
Long before the age of dinosaurs, the earth had been covered by enormous amounts of vegetation.
The climate was hot and extremely wet.
A huge layer of water vapor surrounded the planet, preventing sunlight from reaching the surface as it does today.
So where had all that heat come from?
Perhaps from inside the earth itself.
My uncle had many theories about the subject, but one thing seemed certain to me: deep inside our planet, an enormous fire had once been burning.
Its heat had reached almost to the surface.
The plants living in that ancient world received little or no sunlight, so they had no flowers, no pleasant smells, and no beautiful buds.
Yet their roots drew powerful nourishment from the hot earth beneath them.
There were few trees as we know them today.
Instead, the land was covered with enormous masses of grasses, mosses, vines, and other primitive plants.
There were countless varieties of them.
Eventually, all that vegetation became the coal we now burn.
The earth’s crust was constantly moving above the boiling material deep inside the planet.
Cracks opened.
Land collapsed.
Huge masses of vegetation were buried beneath water.
Over immense periods of time, natural chemical processes transformed those plants.
First they became peat.
Then, under pressure and the influence of gases and underground fermentation, they slowly turned into mineral coal.
That was how the enormous coal deposits of the world had been created.
As I looked at the vast untouched layers around us, I remembered everything I had learned at school.
These coal deposits were unbelievably rich.
But nobody would ever mine this particular place.
It was far too deep.
The cost would be impossible to justify.
Besides, coal already existed much closer to the surface in many parts of the world.
These underground deposits could remain untouched for as long as the earth itself existed.
While I was lost in these geological thoughts, the others continued walking.
The temperature remained almost unchanged from the earlier parts of our journey.
But there was something else I noticed.
A powerful smell filled the passage.
I knew what it was immediately.
“Fire damp,” I thought.
The tunnel was full of the dangerous gas that killed so many miners.
A single spark could cause a terrible explosion.
Hundreds of people could die in an instant.
Fortunately, we were using the Ruhmkorff electrical lamp.
If we had been carrying ordinary torches, the flame would have ignited the gas and blown us all to pieces.
We would never have left the coal mine alive.
We continued through the strange underground world until evening.
My uncle was becoming increasingly impatient.
The tunnel still continued horizontally.
He clearly wanted the path to descend.
But it did not.
The darkness ahead and behind us was so thick that we could not see how far the tunnel extended.
I began to fear that it might never end.
Perhaps we would be forced to walk through this endless passage for months.
Then, at six o’clock, we suddenly stopped.
There was a wall in front of us.
I looked to the right.
Nothing.
I looked to the left.
Nothing.
Above us?
Solid rock.
Below us?
Solid rock.
There was no way forward.
The earth itself seemed to be telling us:
“No passage.”
I stood there in shock.
Hans simply folded his arms.
My uncle said nothing for a moment.
Then suddenly he laughed.
“Well, well! Perhaps this is for the best.”
I looked at him in surprise.
“Now I understand what has happened,” he continued. “We are definitely not following Saknussemm’s route.”
He turned toward us.
“There is only one thing to do. We must go back.”
He sounded completely confident.
“We’ll rest tonight. Within three days, I promise you, we’ll be back at the place where the two tunnels divided.”
“Yes,” I said weakly. “If we still have enough strength to get there.”
My uncle frowned.
“Why wouldn’t we?”
“Because tomorrow we will have no water.”
He stared at me.
“Our last drop is almost gone.”
“And apparently your courage is disappearing with it,” he said sternly.
I had no answer.
I turned onto my side.
I was completely exhausted.
Within minutes, I fell into a deep sleep.
But even in my dreams, I was thinking about water.
When morning came, I woke feeling no better.
At that moment, I would have traded an entire diamond mine for one glass of cold, pure spring water.