Word problem
: A brilliant and beautiful girl has only enough patience for three hours of irritation. Her annoying twin brother tells fibs about her for fifteen minutes the first night, twenty minutes the second night, twenty-five minutes the third night, and so on. How long will it take her to blow her top?

Never mind, I already know the answer.

My pain-in-the neck brother, Zeke, has already told you of our first adventures with the Undies (the people, not the unmentionables).

But before I report on what happened next,
I've got to set the record straight. Typical Zeke, he's gotten it all wrong.

Not the part about the zombies and the mini-dinosaurs, or our vow to help recover some magical objects and free the people of Underwhere from the UnderLord. That's correct.

But he makes me sound like some kind of priss who cares more about hair conditioner than about saving the world.

And
that's
just not true.

Using the proper conditioner
is
an important part of hair care. But it's not as important as keeping some evil dwarf from taking over your planet, okay?

And I'm so
not
a priss. Zeke and our neighbor Hector are typical boys; they never stop to think. I'm the sensible one. The one who says, “Gee, maybe we shouldn't jump into that shark-infested water with hands full of raw steak.”

Can I help it if I always know the right thing to do?

Honestly.

But back to what happened next.

We were just getting home from schoolâZeke and I and our neighbor Hectorâwhen a wild-haired old man ran up our driveway. He looked like some kind of scientist. The mad kind.

“I need your help!” he cried. “My artifact is missing, and I'm afraid the UnderLord might have taken it.”

“Let's go!” shouted Zeke.

“Wait,” I said. “Who are
you
?”

The old man smoothed his hair. “Oh, I'm Dr. J. Robert Prufrock, a friend of your great-aunt Zenobia.”

“Good enough for me,” said Zeke.

I grabbed his arm. “But how do we know he's
really
a friend of Great-aunt Zenobia?”

Zeke rolled his eyes. “Duh, because he
said
so.”

“That's right,” said Hector. “And if Dr. Prufrock doesn't know whose friend he is, who would?” Good old Hector. He's cute, but he's as bad as Zeke.

“Remember âstranger danger'?” I said. “Hello? Have you guys even heard a word of those lectures we've had since kindergarten?”

Dr. Prufrock held up his hands. “Children, please. Every minute counts.”

I crossed my arms. “We don't know you, and besides, we really should do our homework first.”

“Steph!” cried Hector and Zeke together.

“Well, we
should
,” I said.

It always happensâI'm right, but they gang up on me.

Hector's orange cat, Fitz, wound around my ankles and grumbled. “Mrrow reer row
ree
roww.”

“You too, kitty cat?” I said.

The white-haired man fumbled in his coat pockets. “By Odin's elbows,” he muttered, “we're running out ofâ¦ah!”

“Running out of
ah
?” said Zeke.

Dr. Prufrock held out a photo. “
Now
do you believe me?”

The picture showed a cave mouth and three really old people in khaki pants: Dr. Prufrock, some lady with a pinched face, and our great-aunt Zenobia.

“Looks like Indiana Jones's grandparents,” said Hector.

“I resent that,” said Dr. Prufrock. “Who's Indiana Jones?”

Zeke tapped the photo. “See, I told you. They're friends.”

“Okay,” I said. “But this better be quick.”

Dr. Prufrock hustled us into his car, a dented gray thing. I brushed off the front seat carefully
before getting in. Fitz hopped onto my lap.

With a roar, the car belched smoke and poked down the street.

This was not going to be quick.

Dr. Prufrock filled us in. “I need help, and I can't trust anyone outside our little circle.”

He took the corner too sharply, and I was smushed into the side door.

“Of the three people in that photograph,” he continued, “Zenobia is gone, and Amelia is in hiding. If I can't trust Zenny's family, whom can I trust?”

Zenny?
I thought. Had they been boyfriend and girlfriend, finding love among the ruins?

Awwwâ¦how romantic. Even wrinkled love is kind of sweet.

“How can we help, Dr. Prufrock?” I asked.

“What do you know about the UnderLord?” said the old man.

He pulled into the oncoming lane to pass a school bus. Drivers honked and slammed on their brakes. Fitz's claws dug into my leg.

Zeke clung to the seat back. “He was trying to take over our world.”

“By posing as the rapper Beefy D,” Hector added.

“Suffering Socrates! It's worse than I thought,” said the doctor.

Hector smirked. “And you didn't even hear him rap.”

Distracted, Dr. Prufrock drove over the curb and sideswiped a trash can. Don't they ever make old people take driving tests? Honestly.

Then something struck me. “Wait, have you been to Underwhere?”

“With Amelia and Zenobia,” he said. “That's where we found the artifacts.”

“What artifacts?” said Zeke.

“The Throne, the Brush, and the Scepter,” said the doctor. “And by all that's holy, they must not fall back into the UnderLord's hands.”

He stomped on the brakes, and the car sputtered to a halt.

“Ah, home, sweet home.”

Dr. Prufrock's house was a lot like himâtall, messy, and needing a new coat of paint. What is it about guys and dirt?

He led us through the front door and down a dusty hall. “I last saw it here, in the library.”

We peeked into a room. Books lined the walls and rose from the floor in piles like ruined towers. A sea of papers lapped around them. Crusty dishes and coffee mugs sat everywhereâsome with flies, some without. Rumpled clothes, empty shoe boxes, three chessboards, a stuffed anaconda, and a full suit of rusty armor completed the picture.

“Um, Dr. Prufrock?” I said.

“Yes, Stephanie?”

“Are you sure you haven't just
misplaced
your artifact?”

He frowned and looked about. “Erâ¦well, yes, pretty sure.”

Zeke put his hands on his hips. “Soâ¦what are we looking for?”

“Well,” said Dr. Prufrock, “the artifact looks rather like a common toilet brush.”

Hector and Zeke snickered. I could have predicted that.

“Only it's larger and painted with colorful runes,” said the doctor.

Hector gazed out the window. “Has it also got golden bristles?” he asked.

“Yes,” said Dr. Prufrock.

“And is it about
so
long?” Hector held his hands apart.

“Why, yes.”

“With some kind of sparkly ring around the handle?”

“That's it exactly!” said the doctor. “Do you see it?”

Hector pointed outside. “Sure, it's in that cat's mouth.”

CHAPTER 2
Cat Burglar

We ran to the glass and peered into the backyard. Hector was right. In the shaggy grass sat a familiar, fat brown cat with a fancy toilet brush in his mouth.

“Isn't that
your
cat?” said Hector.

“Meathead?” said Zeke.

“Meathead!” I cried.

“Mrrow!” said Fitz.

Meathead looked up at us.

He had run off a few weeks ago. I always expected Meathead to return sometime. But never with his own toilet brush. (He wasn't
exactly a clean kitty.)

Zeke pounded toward the half-open back door, Hector and I right on his heels. We burst out onto a porch.

“Slow down!” I hissed. “You'll spook him.”

For onceâa miracleâZeke listened. He stopped short. “H-e-e-e-re, Meathead,” he said. “N-i-i-i-i-ce kitty. Give us the brushy-wushy.”

Meathead backed up a step.

I elbowed Zeke aside. “Let
me
do it. He probably remembers the time you painted stripes on him.”

“What do you mean?” said Zeke. “Meathead
liked
playing skunk.”

I sat on the steps and held out a friendly hand. “Here, kitty kitty.”

Meathead blinked. But he didn't drop the brush.

Slowly and carefully, I got to my feet.

“Easy now,” said Dr. Prufrock from behind us.

We crept forward.

The cat backed up another step.

“Good thing ol' Meatbrain doesn't know how valuable that thing is,” Zeke said.

Meathead's ears pricked up. Brush in mouth, he turned and trotted for the side yard.

“Brilliant move, basket case!” I cried, giving chase.

“What'd I do?” said Zeke, joining me.

I spared him a glance. “Fitz can understand English; why do you think Meathead can't?”

Meathead plunged into the overgrown bushes beside the house, the tip of his tail wriggling through the jungleâprobably all poison ivy and prickly plants. (Dr. Prufrock's gardening was about equal to his housekeeping.) We waded through the bushes anyway.

“Give us the brush, fleaball!” cried Zeke.

“That's it, genius,” I said. “Sweet-talk him.”

Meathead reappeared on the far side of the thicket and bolted across the front lawn. Ten seconds later we followed, running full out.

And we might have caught him tooâif not for the two hairy, black-suited men blocking our path.

“Greetings, children,” said the chubbier man.

“Can't talk now,” said Zeke, dodging past. The taller man snagged his arm.

“Hold on,” said the man. A monster-sized mole on his cheek made it hard to look him in the eyes. (Or into the sunglasses that covered his eyes.)

It was our old friends, the nameless spies from H.U.S.H., an agency so secret, even
they
didn't know what H.U.S.H. stood for. They had forced us to spy in Underwhere. We called them Agent Belly and Agent Mole.

And they were anything but friends.

“Let's talk,” said Agent Belly.

From the sidewalk just beyond them, Meathead turned to watch.

“Sorry, but we have to catch our cat,” I said.

“No,” growled Agent Mole, “you don't.”

Hector flinched. I glanced back at the house for help, only to see Dr. Prufrock duck behind a curtain. Where's a grown-up when you need one?

“Um, maybe we can spare a minute,” I said.

Meathead ambled away with the brush, tail held jauntily, mocking us.

“Aww,
sheesh
,” said Zeke.

Agent Belly adjusted his fake black beard. Mole straightened a fake mustache. I suppose they thought their disguises were good. And maybe they wereâfor a kindergartner.

“Children,” said Belly, “we appreciated the, er, magic rock you brought back from your last trip below.”

Magic rock.
A nice description for the dhow-
naught, an enchanted stone that would happily bite your hand off.

“It had our team quite fascinated,” he continued. “But nowâ¦”

“Need more,” grunted Agent Mole.

Belly smiled. “Yes, the rock isn't enough. We want something better.”

“Like what?” asked Zeke. He looked where Meathead had gone. Mole tightened his grip.

“An object of power,” said Agent Belly. “You know, a wand, a crystal, a gizmo that people down there use for making magic?”

Zeke, Hector, and I traded glances. We knew that Meathead was carrying a power object. But we didn't want to just hand it over to the men from H.U.S.H. when our friends in Underwhere needed it so badly.

I chewed my lip. Soon Meathead would be long gone.

“That brush,” I said.

“No!” said Zeke.

“Speak,” said Agent Mole.

“That brush our cat was carrying? It's a power object.”

Agent Belly smirked. “A
toilet
brush? You must think your government likes to hire fools.”

“It's true,” said Hector. Mole glared. Hector held up a hand. “I mean, not true that we think you're foolsâtrue that the brush is magic.”

Agent Belly scratched under his fake beard. “Come now, children.”

Typical grown-ups. They didn't believe us when we told the truth. Fine. I knew how to deal with that attitude.

“That's right, Hector,” I said, meaningfully. “A land with enchanted rocks couldn't
possibly
produce a magic toilet brush. Stop pretending.”

Hector frowned. Then he got it. “Ri-i-ight.
That
brush isn't magic.”

“It isn't?” said Zeke, clueless as usual.

I elbowed him. “Of
course
it isn't.”

“Not so fast,” said Agent Belly. “You can't slip one over on us.”

Mole nodded. “Go get the brush.”

“And don't disappoint us,” said the chubby spy. “It would be a shame if you flunked out of elementary school because your grades suddenly plunged.”

“Our
grades
?” I said, gripping my skirt. “But you can't change our grades.”

“Can't we?” said Belly. “The government computer network is a marvelous thing.” He smiled and gave us a finger wave. “Ta, ta.”

Mole released Zeke. We took off running.

In a flash, we hit the sidewalk and sprinted to the corner. The streets ran in four directions.
All four were cat free.

“Dang!” said Zeke. “Now we'll
never
find him.”

“Not necessarily,” said Hector.

I turned to him. “What do you mean?”

“Oh,
Fitzie
!” he called.

His cat popped out of the hedge and padded up to us. “Mrrrow reow?”

“How'd you like to earn a bowl of Tuna Cat Chow?” asked Hector.

Fitz looked unimpressed. He was good at it.

“
Fresh
tuna?” said Hector.

Fitz rolled his eyes.

“Okay,” said Hector. “You win. A whole side of salmon.”

Fitz purred. “Murr reer roor?” he asked.

Hector waved a hand at the empty intersection. “Follow that cat!”

Sniffing the breeze, Fitz took the left-hand street. We followed.

Two houses down, he froze and stared at some bushes. His tail twitched.

“Is it Meathead?” I asked.

Fitz sank into a crouch. The bushes rustled. Something parted the grass.

A field mouse.

“Fitz!” Hector pulled on the cat's collar. “I said
cat
, not
mouse
.”

Fitz gave him a baleful look, but he got back on track.

Three houses down, he squeezed through a half-open gate into a construction site.

A rotten-egg smell greeted us, stronger than the funk from Zeke's dirty laundry pile. Something about it seemed familiar.

“Hey, isn't this where we came out after our first trip to Underwhere?” I said.

Zeke looked around. “I never thought I'd say these words, but you're right.”

The structure was more complete than when we'd last been here, a week earlier. It was as odd as the building going up near our houseâall lopsided and oversized. But here the walls were solid, and windows glinted from the top story.

Fitz stepped through the cavelike entrance. He made for a corner room.

“That's the tunnel we came up through,” said Hector.

We stopped in the doorway. A strong wind plucked at our clothes. It blew from a dark hole in the center of the floor.

Fitz sat and looked up at us, then at the hole.

“Down there?” I said.

“
That's
where Meathead went?” said Zeke.

The cat gave him a
well, duh
stareâthe same kind I often give my brother.

Zeke and I looked at each other.
Oh, boy.

“Okay,” he said. “Down the hatch.”

As he walked over and slid down the portal, I thought,
I picked a fine day to wear a skirt
.

Then I clapped my hands to my thighs, and down I went after him.