They walked, and Charlie told the hulder everything he had seen and heard: the Sinister Man, and the Iron Cog, and the Anti-Human League, and his father being called Dr. Singh, and THIS ISN’T JUST A HAT, MY GOOD MAN. IT’S A CAVENDISH, and the men with cutlasses who said they were policemen, and the two hulders, one of whom smoked. Henry Clockswain listened closely and watched with rapidly blinking eyes, and Charlie realized he hadn’t taken the time to tell the story to the kobold.

“Scentless tobacco, hmm?” the hulder rumbled.

“Do you know him?”

“Doesn’t ring a bell,” Grim Grumblesson said, “but I’m not a smoker. Don’t worry; there just aren’t that many hulders in London. We’ll find him.”

“Maybe we should go around to all the tobacconists,” Mr. Clockswain suggested.

“We’ll help you,” Natalie de Minimis promised.

“It’ll be very ’elpful to ’ave someone as can fly.” Bob kept his eyes on the pixie’s wings as they walked. “Parks an’ rooftops an’ such.”

“Natalie de Minimis will be the next Baroness of Underthames,” the hulder guffawed. “Considerably more useful than just for searching parks and rooftops.”

“My mother’s not dead yet,” the pixie objected. “And besides, you can’t know if I’ll be baroness next or not; the people of Underthames will choose.”

“Do you mean it’s something like an election?” Charlie asked. “Like Parliament?” He remembered that the Almanack had been a little vague on this exact point, and had used words that Charlie didn’t quite understand, such as acclamation and charismatic leadership.

“Something like that,” she said.

“Nothing like that!” the hulder roared. A passing cart driver nearly fell out of his seat. “Parliament is secret ballots and whiskey barrels for the voters and political parties and platforms and greasy backroom deals! The passing of the barony is the clatter of spear on shield by the warrior throng; it’s the cry of favor of the crowd for its chosen leader!”

Charlie could almost hear the cry of the warrior throng as Grim told it. “That sounds exciting.”

“Sounds barbaric.” Ollie scratched his armpit vigorously. “Sounds like something Americans might do.”

“My people follow very old traditions,” Natalie de Minimis said. “We’re here.”

Charlie had been so absorbed in the conversation, he hadn’t paid any attention to his surroundings. Now he found that he was in a cobbled courtyard closed in by windowless brick walls. A narrow alley led into the yard, and a single large storm drain let rainwater flow out, down, and away.

Charlie had read a lot about the sewers. There were rats down there, and worse. Ghouls haunted the empty places just at the edge of cities so they could eat other folks’ garbage and their corpses and, Bap had suggested more than once, their lost children.

And sometimes the ghouls went down into the sewers.

“Where is here?” Ollie asked.

“One of the many doors to Underthames,” Mr. Clockswain said. “It’s signposted, if you know how to read the signs.”

“It is?” Bob asked.

“Pixie gates aren’t secret,” the kobold explained. “They’re just guarded.”

The pixie floated over the storm drain and pointed down at it. “We’ve come by this gate so that you’ll all fit.”

Charlie looked at the storm drain. It was covered by a rack of iron bars, six inches apart. “I don’t see how.”

The troll cracked the knuckles of both hands, bent over, and grabbed the bars. “Stand away,” he grunted, and heaved.

The grate came up from the ground, and Grim hoisted it over his head, with its surrounding wreath of cobbles. It left a hole in the earth at the troll’s feet, neat and rectangular, like the trapdoor opening to a tavern’s cellar. Charlie squinted to get a closer look. He saw stairs, and something else.

“The walls,” he said. “They’re glowing.”

“ ’Tis gloom-moss,” Natalie de Minimis explained. “We see perfectly well in absolute dark, but other folk don’t, and this is a big-folk gate.”

Charlie didn’t remember any mention of gloom-moss in the Almanack.

“Shall we discuss the technical details later?” grunted the troll, who was still holding the slab of iron and stone over his head.

Charlie went first, with the pixie.

The kobold followed, and then, after some muttering and scuffing of feet, Heaven-Bound Bob, with Ollie the Snake on his heels.

Thud!

“Ouch,” muttered the troll.

“Duck, Grim,” the pixie called out.

Charlie heard wordless grumbling, the heavy boots of the hulder on the stairs, and the whoomph! of the gate being replaced.

The passage’s rough walls and ceiling were covered with thick gloom-moss. The glow it gave off was a dull yellow, which seemed to come from inside the moss and shine through its surface like the glow of a lamp behind a lampshade. The gloom-moss glistened as if it were wet, but when Charlie touched it, he found it dry. He stepped carefully over a culvert that crossed the steps to carry any water flow down a red-brick-lined drain big enough to walk in. That must be the sewer. Charlie heard chittering and scratching noises from the sewer and wondered what could be making them.

Hopefully rats. He’d choose rats over ghouls any day.

Among the steady drips of water and with his companions’ footfalls behind him, Charlie followed the pixie down. Centipedes the size of his fingers and roaches the size of his thumbs scuttled out from under his feet as he walked.

“That’s a lovely dress you’re wearing,” he offered.

“Aye, thank you,” she agreed. “I’m coming home after a long time gone, and I’d like to impress my folk.”

“How long was your grand tour?” Charlie asked.

“Two years,” the pixie said. “That’s standard. ’Twasn’t really a grand tour, though. That’s a custom of wealthy English families, and ’tis Grim’s little joke to call it that. There’s a Pixie word for it, but ’tis no use me telling you, since you can’t speak Pixie without wings, and half of spoken Pixie’s too high-pitched for human ears to hear anyway.”

He hadn’t read this in the Almanack either. “Like dogs and whistles, Miss de Minimis?”

She laughed, a very pretty sound like the tinkling of falling water. “That’s not flattering, but aye. Don’t you go whistling on me now. And please, call me Gnat.”

“But you’re the Baroness of Underthames!” It seemed outrageous to call a baroness just Gnat. “Or you will be.”

Gnat shrugged. “No one here’s a baroness yet. The best word in English for what I’ve done is a walkabout. That means a journey taken by the young natives of Australia to see the outside world. Sometimes in English pixies will call it the tithe, too, because a pixie goes when she’s twenty, for two years of her life, which is a tenth. And then, tithe sounds a bit like the Pixie word for a journey.”

“I’m on my walkabout now,” Charlie said. “I didn’t really mean it to happen, but it did.”

“I did my tithe working for Grim. Two years without going back. Two years of no contact with my home, even though I was but a mile away. I learned a lot about humans and hulders, and Whitechapel and London, and folk and the law. Hopefully all that learning, and a wee bit of experience, will add up to wisdom someday.”

“Aye,” Charlie said, and then he felt a little bit silly, but Gnat laughed and that made it okay.

“Hold!” cried a silvery voice below them. Charlie looked ahead and saw that they had come to a closed door without lock, handle, or knob. The door was large and set inside an arch of carved stones. Each stone was an ugly gargoyle face twisted into an expression of rage or hunger or menace. Each gargoyle’s mouth was open, and into each stone tongue was carved a different rune. Charlie had never seen anything like it, even in books.

Eight pixies floated in front of the door, armed with shields and spears. The one in front pointed his spear in the new arrivals’ direction.

“Hold, I said!”

“Hold, yourself, Cousin Hezekiah!” Gnat cried back. “I’m come home to my own mother’s house after a full and successful tithe, and is this the welcome I get?”

Mr. Clockswain, the chimney sweeps, and Grim Grumblesson caught up to Charlie and the pixie and stopped.

“Natalie?” All eight pixies stared. “Can you really be Natalie de Minimis? What are you doing in the company of such a galumphing herd of uplanders, then?”

“And who are you, Cousin Hezekiah, to question me about my choice of companions? And why in Oberon’s name are there so many of you, for just the one door? Open up, and let me and my friends in!” Gnat, who had seemed like a helpful and friendly girl in Pondicherry’s Clockwork Invention & Repair, now fluttered with a fierce arch to her back and fire flashing in her eyes.

“Aye.” Hezekiah sounded tired. “Aye, I’ve orders to take you to the baroness, and I suppose your friends will have to come, too.”

Hezekiah turned in midair and fluttered his wings in a twitchy pattern at the door. The gargoyle-tongue runes lit up all at once. The door swung open with a rush of air, and Charlie thought he heard the gargoyle heads whispering to each other.

“Goodness gracious,” said Henry Clockswain.

Hezekiah led the way. Charlie felt a sharp pang of remorse, realizing that he was likely getting farther from his father with every step. But once Gnat had met her mother the baroness again, Charlie reassured himself, he’d return to the surface with an army of flying pixies, and they’d find Mr. Pondicherry in no time.

And then he promptly lost his train of thought.

The gloom-moss disappeared beyond the doors. The walls of the vast caverns Charlie now entered were studded with jewels of every color. There was light—he couldn’t see where it came from, but it was there—and it spun and flashed in every gem, filling Charlie’s vision with rainbows and whorls and stars and streaks of joy.

In and among the dancing lights Charlie saw nests. They looked just like birds’ nests: piles of thatching woven together. Peeping up over the edges, he saw, were pixie faces. Pixies flew through the air, too, above the nests and high in the caverns and around the edges.

Every pixie dressed like Gnat. Shoe buckles, waistcoats, kilts, hose, and tricorn hats on the male pixies, with long hair in a braid; brocade shoes, close-bodied gowns, jacket bodices, panniers, and hoop skirts on the females, with long hair piled vertically upon their heads. It was like a fancy-dress party of winged insects.

“Goodness gracious!” exclaimed Mr. Clockswain.

Charlie and his party followed a stone-paved road that crawled beneath the teeming cloud, through several caverns, across a stream of water, and past a field of glittering green gemstones. At the peak of a small mound of stone beyond squatted a circle of pillars, half again as tall as Grim Grumblesson and broken off at the tops. It looked like a Greek temple that had lost its roof. At the far end stood a simple stone chair, pixie-sized. Here Hezekiah barred the company’s way with his spear.

In front of the chair hovered a strange cast of characters, posed in a scene. It took Charlie a moment to figure out what they were up to. “Tableau vivant,” he murmured. “They’re making living art.”

He’d heard his father mention tableau vivant, but he’d never understood quite what it was.

The pixies all posed together to look like a painting. A pixie in a pink cape, who strongly resembled Gnat, hovered above the others. She confronted a shy pixie who wore a blue toga and had sad eyes; he stood on the ground and turned his shoulder. Behind Pink Cape stretched a procession of revelers holding joints of meat and small snakes and tambourines. A stuffed dog and two purring leopard kits on chains completed the scene. They all held perfectly still, and Charlie wondered what painting they were imitating.

A crowd of pixies had gathered around. Some of them fluttered low to the ground and others higher, even directly overhead. Charlie was standing inside a living bubble formed entirely of pixies.

Almost all of them armed with spears.

The tableau actors held their pose.

Grim shuffled from one foot to the other.

Crack! A paving stone under the troll snapped in two.

“Agh!” Pink Cape threw her hands up in exasperation. She fluttered down and flung herself into the seat, and the other actors all relaxed. All except Blue Toga, who stayed on the ground and kept his back partly turned to Pink Cape.

“Cousin Elisabel,” Natalie said to Pink Cape. “You’re in my mother’s seat.”

“My old auntie’s dead, Cousin Natalie,” said the seated pixie, “and the seat is my own now. Have you returned to make a claim, then?”

Gnat’s wings fluttered a little faster, and Charlie thought he heard Grim Grumblesson mutter under his breath. Blue Toga looked at Gnat, and Charlie saw a glimmer of hope in his eyes.

“I’ve no wish but to come back to my own home in peace, Cousin Elisabel,” Gnat said, “and see my fine cousin Seamus. I’m no one you should worry about, no one special at all, just a pixie come home from her tithe. I’ve not come to make a claim today.”

“Good.” Elisabel gestured with her hand to the spear-wielding crowd. “Lock her up, her and all her uplander friends.”