He was becoming increasingly worried about his supply of water. As he'd boarded the Miners' Train, the Colonists had thoughtfully provided him with a full canteen, a satchel of dried vegetables of some type, some meat strips, and a packet of salt. He could ration the food, but the problem was definitely the water; he hadn't been able to find a fresh source from which to replenish his canteen for two whole days now, and he was running perilously low.

Having rearranged the kindling, he began to knock two chunks of flint together until a spark leaped into it and a tiny flickering flame took hold. With his head resting on the grit floor, he gently blew on the flame and fanned it with his hand, nurturing it until the fire caught, bathing him in its glow. Then he squatted down next to his open journal, sweeping the layer of dust from the pages, and resumed his drawing.

What a find! A circle of regular stones, each the size of a door, with strange symbols cut into their faces. Carved letters collided with abstract forms — he didn't recognize these characters from all his years of study. They were unlike any hieroglyphs he'd ever seen before. His mind raced as he dreamed of the people who had made them, who had lived far below the surface of the earth, quite possibly for thousands of years, yet had the sophistication to build this subterranean monument.

Thinking he heard a noise, he suddenly stopped drawing and sat bolt upright. Controlling his breathing, he held completely still, his heart pounding in his chest, as he peered into the darkness beyond the fire's illumination. But there was nothing, just the all-pervading silence that had been his companion since the start of his journey.

"Getting jumpy, old man," he said, relaxing again. He was reassured by the sound of his own voice in the confines of the rock passage. "It's just your stomach as usual, you stupid old fool," he said, and laughed out loud.

He unwound the shirt from around his mouth and nose. His face was cut and bruised, his hair was matted, and a straggly beard hung from his chin. His clothes were filthy and torn in places. He looked like an insane hermit. As the fire crackled, he picked up his journal and concentrated on the circle of stones once again.

"This is truly exceptional — a miniature Stonehenge. What an incredible discovery!" he exclaimed, completely forgetting for the moment how hungry and thirsty he was. His face animated and happy, he continued with his sketching.

Then he put down his journal and pencil and sat unmoving for a few seconds as a faraway look crept into his eyes. He got to his feet and, taking the light orb in his hand, backed away from the fire until he was outside the stone circle. He began to stroll slowly around it. As he did so, he held the orb to the side of his face like a microphone. He pursed his lips and dropped his voice a tone or two in an attempt to mimic a television interviewer.

"And tell me, Professor Burrows, newly appointed Dean of Subterranean Studies, what does the Nobel Prize mean to you?"

Now walking more quickly around the circle, a jaunty spring in his step, his voice reverted to its normal tone and he moved the light orb to the other side of his face. He adopted a slightly surprised manner with pantomime hesitancy.

"Oh, I… I… I must say… it was truly a great honor and, at first, I felt that I was not worthy to follow in the footsteps of those great men and women—" At that very moment his toe caught against a piece of rock, and he swore blindly as he stumbled for a few paces. Regaining his poise, he began to walk again, simultaneously continuing with his response. " — the footsteps of those great men and women, that exalted list of winners who preceded me."

He swung the orb back to the other side of his face. "But, Professor, the contributions you have made to so many fields — medicine, physics, chemistry, biology, geology, and, above all, archaeology — are inestimable. You are considered to be one of the greatest living scholars on the planet. Did you ever think it would come to this, the day you began the tunnel in your cellar?"

Dr. Burrows gave a melodramatic «ahem» as the orb changed sides again. "Well, I knew that there was more for me… much more than my career in the museum back in…"

Dr. Burrows's voice trailed off as he ground to a halt. He pocketed the orb, plunging himself into the shadows cast by the stones as he thought of his family and wondered how they were getting along without him. Shaking his bedraggled head, he slowly shuffled back into the circle and slumped down by his journal, staring blankly into the flickering flames, which grew more blurred as he watched them. Finally he removed his spectacles and rubbed the moisture from his eyes with the heels of his hands.

"I have to do this," he said to himself as he put his spectacles back on and once again took up his pencil. "I have to."

The firelight radiated out from between the stones in the circle, projecting shifting spokes of gentle light onto the floor and walls of the passage. In the center of this wheel, totally absorbed, the cross-legged figure grumbled quietly as he rubbed out a mistake in his journal.

He didn't have a thought for anyone in the world at that moment; he was a man so obsessed that nothing else mattered, nothing at all.

As a fire sputtered in the hearth, Mr. Jerome reclined in one of the wingback armchairs, reading his newspaper. From time to time, the heavily waxed pages flopped waywardly, and he flicked his wrists reflexively to straighten them up again. Will couldn't make out a single headline from his vantage point at the table; the blocky newsprint bled into the paper to such an extent that it looked as though a swarm of ants had dipped their feet in black ink and then stampeded across the pages.

Cal played another card and waited expectantly for his brother's response, but Will was finding it impossible to keep his concentration on the game. It was the first time he'd been in the same room with Mr. Jerome without being on the receiving end of hostile glances or a resentful silence. This is itself represented a landmark in their relationship.

There was a sudden crash as the front door was flung open, and all three looked up.

"Cal, Will!" Uncle Tam bellowed as he blundered in from the hallway, shattering the scene of apparent domestic bliss. He straightened himself up when he saw Mr. Jerome staring daggers at him from his chair.

"Oh, sorry, I…"

"I thought we had an understanding," Mr. Jerome growled as he rose and folded the paper under his arm. "You said you wouldn't come here… when I'm at home." He walked stiffly past Tam without so much as a glance.

Uncle Tam made a face and sat down next to Will. With a conspiratorial wave of his hand, he indicated to the boys to come closer. He waited until Mr. Jerome's footsteps had receded into the distance before he spoke.

"The time has arrived," Tam whispered, extracting a dented metal canister from inside his coat. He flipped off the cap from one end, and they watched as he slid out a tattered map and laid it over their cards on the tabletop, smoothing out the corners so that it lay flat. Then he turned to Will.

" Chester is to be Banished tomorrow evening," he said.

"Oh, God." Will sat up as if he'd been shocked with an electric current. "That's too sudden, isn't it?"

"I only just found out — it's planned for six," Tam said. "There'll be quite a crowd. The Styx like to make a spectacle out of these things. They believe a sacrifice is good for the soul."

He turned back to the map, humming softly as he searched the complex of grid lines, until finally his finger came to rest on a tiny dark square. Then he looked up at Will as if he'd just remembered something.

"You know, it's not a difficult thing… to get you out, alone. But Chester, too, that's a very different kettle of fish. It's taken a lot more thought, but" — he paused, and Will and Cal stared into his eyes — "I think I might have cracked it. There's only one way you escape to the Topsoil now… and that's through the Eternal City."