"However, as far as we can tell," Dennis said, "that wall's at least eighty feet thick, even at its narrowest point. And no fungus was present here before we brought in a sample from Pandemonium. Speaking of..." Nell saw that the shelves to each side carried beds of glowing fungus: fleshy, lacy rinds like tripe ridged with mushroom caps glowed in six colors that were separated into squares. "We grew all of this from one sample scooped from Pandemonium," Dennis said. "It divided itself by color as it spread to each bed."

"Rainbowfire," Nell murmured, delighted to see it up close.

"That's a good name, Nell," Sasha said.

Dennis nodded. "Very apt."

"What does it feed on?" Nell asked.

"In each bed there is a different kind of organic matter. Each color of fungus seems to colonize a different fertilizer. Either that or different nutrients cause them to change color the way hydrangeas turn blue or pink depending on the pH of the soil." Dennis shrugged. "We're not sure."

"So why is it growing in the cracks on the wall, then? It must be eating something organic, right?"

"Yes. We think that a cave-in in Pandemonium may have impacted that wall long ago and caused those fractures. Over many millennia, organic material infiltrated through the cracks. The pattern on the wall did not show up until we brought samples of-'rainbowfire,' as you call it-from Pandemonium into the farm. So we think the spores, which fly everywhere, must have taken root in the nutrients inside the cracks."

"Yuck!" Sasha covered her mouth. "Spores are flying everywhere?" She choked, coughing.

Nell laughed. "Don't worry, honey. If it hasn't killed everyone already, it's probably OK."

Ivan lifted his leg, and a lower flat of orange rainbowfire turned blue where the canine squirted a yellow stream of urine.

Sasha squealed with laughter. "Ivan!"

"It's OK," Dennis said. "That's actually quite interesting."

He and Nell both stooped to look at the color change.

Sasha rolled her eyes. "You guys are weird!"

"We kind of hope the spores will spread to other sectors," Dennis said. "At least they would provide some light there. Until the power is turned on, of course."

"Where did you get the sample of rainbowfire?" Nell asked.

"We scraped it from the landing of the gondola."

"Gondola? The gondola that goes across Pandemonium?" Nell turned to him, grinning excitedly.

"Yes."

"Have you ridden on it?" Nell asked, an eager spark igniting in her eyes. "Does it go to the island in the middle of the lake?"

"No, I haven't ridden it." Dennis wiped his glasses. "I really don't think it's still working."

"There's a tram that goes from Papa's tower to the palace," Sasha bragged. "That's what I use to visit him. It's really fun, Nell!"

"That does sound like fun, Sasha. So, how do you combat mildew down here?" Nell asked.

"Grrr! If you two are going to talk about mildew, can you give me some carrots to feed Ivan, Dennis?"

"OK, Sasha," Dennis said. "Come this way."

He led them back to the carrot beds.

8:58 A.M.

Maxim shouted: "Sector Three, Boris!" and rapped on the tinted glass behind him.

"Khorosho!" replied his driver.

Maxim tapped his knees, facing Geoffrey. "How is your honeymoon, my friend?"

Geoffrey grinned. "Fantastic. You're a madman, Maxim. I can't wait to get back to Hell's Window. Nell thinks there must be another window downstairs, underwater?"

Maxim laughed. "I promise you there is much more to see. In due time! This morning we are on verge of starting Pobedograd's heart. Without power, this city will die. When plant is on, day will replace night. We will no longer be dependent on surface for power. I appreciate your company this morning, Geoffrey. Tell me. You were on Henders Island, I believe?"

"Yes." Geoffrey nodded. "I survived Henders Island."

"What would you say was best strategy for surviving there, eh?"

Geoffrey shrugged at the random question. "Leaving," he said.

Maxim raised a wry eyebrow. "What else?"

Geoffrey found the question odd, but not unusual. "Well, hendros got around by killing large animals to draw predators into feeding frenzies. It seemed to work. It saved my life once, in fact."

"Ah. Very interesting. A metaphor for civilization, I think."

"Perhaps. Also, many animals on the island sprayed warning pheromones when they detected salt water, an adaptation to life on a shrinking landmass surrounded by ocean. Salt water acts like a tranquilizer on the copper-based metabolism of Henders organisms, paralyzing and killing them, since they could not hypo-osmoregulate. Spraying salt water on the organisms caused them to spray a warning pheromone, which turned out to be a rather effective repellent."

Maxim nodded with great interest. "That is very strange."

"No. Not really. Crows rile up ants to get them to attack and spray formic acid on their feathers, which is an effective repellent for parasites."

"Really?"

"I watched one crow sit for ten minutes with its wings extended over an ant trail." Geoffrey laughed. "Crows are smart."

Maxim grinned. "I see I got the right man for this job." He laughed and slapped Geoffrey's knee. "I like you, Geoffrey. You have passion for your work. That is good!"

They passed work details along the streets, and Geoffrey noticed all the men stopped and stared with blank eyes at the limo as it quickly passed. The expression on the men's faces chilled Geoffrey as the car turned onto the street they had taken when they first arrived, which proceeded north at the eastern edge of the city.

"Pobedograd will be paradise," Maxim said in a forceful voice that was one part dreamer and one part gangster, Geoffrey thought as the mogul continued. "We have natural hot springs, riverfront penthouses, casinos, nightclubs, theaters, spas, swimming pools, art galleries-we even have a unique ecosystem for scientists to study, eh, Geoffrey? Timeshares and property are available to all those who help make my dream come true. You are certainly among those. In case of worldwide catastrophe-which seems more likely every day-such refuge will be valuable. Don't you agree? The population of this city is a cross section of best world has to offer. People of every profession are represented." Maxim considered, and grinned. "Except for politicians. They can go to hell, instead. There is no room for them here. We don't need their laws."

"Many of the world's biggest crooks could afford a ticket to Pobedograd, I guess," Geoffrey speculated. "And probably wouldn't mind a place like this to hide from the law."

Maxim frowned. "Do not worry, Geoffrey. I am businessman. I must have principles to stay in business, unlike politicians. And you should know that heroes are often branded criminals by villains."

"And you are the judge of who is who here. Am I right?"

"Yes. Here, I am."

"I see. Well, in the event of disaster, it's good to know there's a place we can come to live in a dictatorship," Geoffrey mused, challenging the oligarch with a wry look.

Maxim seemed to enjoy his friendly jab. "As I said, Geoffrey, I'm a benevolent dictator. Laissez-faire!"

"Yes, but money wouldn't be worth much down here in the event of a global catastrophe," Geoffrey said, probing.

"You are right, again. I accept only value as payment, in goods or services, along with lifelong commitment to Pobedograd's security. When we are self-sufficient, people will be able to survive here for generations without ever leaving."

Geoffrey concealed his surprise at the statement. "Well. I would hope leaving is always an option."

"Of course." Maxim grinned. "So do I. But why would anyone want to, I wonder?"

"They justified the Iron Curtain that way, didn't they?"

"A curtain can be a shield, too, Geoffrey, when it's made of iron."

They stopped before the northern gate marked SECTOR TWO. Guards activated the steel door, and the heavy barrier rolled aside.

The limo entered the desolate medieval labyrinth of Sector Two, which seemed to be a grid of streets around square blocks of two-story buildings with crude facades carved into bands of limestone and salt. A hundred yards in, they turned right, and sixty feet later, they stopped before another steel door painted with tall red letters: SEKTOP 3. Two guards rose from their chairs and activated the door.

They passed through a short tunnel that opened on a three-story building on the north side of a short street that dead-ended 150 feet straight ahead at another guarded door that read SEKTOP 4 in giant letters.

A black SUV idled in front of the building as their limo pulled up and stopped behind it. Geoffrey noticed that the windows in the second story of the building were lit. Over the entrance, an entablature read: No Latin lettering this time. According to Geoffrey's faint memory of the Cyrillic alphabet, the first word might be "observatory." But that made no sense under a mountain. "What is this building?" he asked.

"Hospital," Maxim said as he rolled down the window.

Geoffrey smelled the gasoline exhaust waft through the crack; this place was worse than Hong Kong, he thought.

Maxim pushed his head out of the window and yelled, "Let's go!"

The black Suburban abruptly pulled out in front of them.

The steel door at the end of the street slid open as two guards stepped aside.

Maxim rolled up the window as his armored limo took off behind the SUV, and Geoffrey noticed the sentries quickly close the gate behind them as they accelerated.

9:07 A.M.

"Ivan hasn't eaten anything but carrots today, but he needs to go doody. I'm taking him for a walk down Compost Alley."

"OK! That's Ivan's personal dog run," Dennis explained. "We compost everything here, of course."

"When you're done talking about irrigation, we'll be over there." Sasha rolled her eyes. She motioned Ivan to follow her and disappeared with the dog under a shelf of algae flasks.

"Wow," Nell said. "She's something."

"She certainly is," Dennis nodded and looked at his watch. He frowned, sighing.

"What's the matter?"

"The initiation of our power supply seems to have been postponed. Once again.... I had hoped the lights would be on for our tour today," he apologized. "Most of the projects we are working on will require a strong light source, of course...." Dennis looked up at the dimly lit lighting structure hanging from the high ceiling. "They must be having more trouble."

"Nell!" Sasha called. "Come here!" Her voice echoed across the rows.

Dennis shrugged. "You might as well go with her. There's not much more to see at the moment."

"Well, it was nice meeting you, Dennis. See you around." Nell shook his hand and ducked under the lower bench of algae jugs. "Where are you?" she called from the next row over.

"Over here!" Sasha's voice sang like an opera singer.

"OK." Nell stooped and crawled under the lower shelf of another row of bottles.

"One more!" Sasha shouted, and Nell climbed under the next row. As she came out from under, Sasha kissed her on the forehead and Ivan licked her face. "Ha ha ha!"

Nell laughed as she climbed to her feet and dusted off. "There you are!"

"Come on!" Sasha ran, leading Ivan and Nell with a lavender flashlight she had taken out of her purse and pointed north into the dark.

"Where are we going?" Nell asked.

"A secret passage!"

"Where does it lead?"

"The palace, of course! Crummy old Stalin wanted to have lots of food for himself, so he built a secret passage to the farm!"

"Oh. Wow!"

Sasha and Ivan took Nell through the dark, led more by Ivan's nose than by Sasha's flashlight, and they finally arrived at the northwest corner of Sector Five. The young girl, her white clothes now smudged with dirt like her snow-white dog, opened a small panel in the rock face, revealing a hatch wheel. She jumped up as she cranked it down, twice. A door popped out, disguised to look like part of the natural wall. Sasha and Ivan wedged it open to a tunnel, which coursed to the left and right.

"The palace is this way!" Sasha whispered as Ivan took off to the right.

Nell followed her through the door, and Sasha pulled it closed. Then they ran after Ivan.

"Where does the other direction go?" Nell asked.

"To your honeymoon suite!" Sasha laughed. "That's where Stalin took his sweeties!" she shouted over her shoulder. "I think it goes to the railroad in Sector Seven, too. So he could make his getaway back to Moscow!"

Nell tried to catch up with the precocious princess through the barrel-vaulted corridor that headed steeply uphill. "Have you gone down there?" Nell panted. "Back the other way?"

"No," Sasha said. "I tried to go down there once, but I saw a ghost! A really scary ghost. Ivan tried to bite it."

Nell sweated in the warm, stuffy air as she followed Sasha up the stifling passage, with a few glances over her shoulder at the deep dark behind them.

They finally reached a wall with a hatch, which opened into a room with a red velvet curtain similar to the one in the conservatory, but only a third of the size.

Sasha closed the door behind them, breathing dramatically. "I'm pooped!" she whispered.