Bax’s mom drove him to Andres’s house on Saturday afternoon. Everyone from the UDM class was there when he arrived.

It was a warm and welcoming house, and Bax was interested to see how the Padillo family had adapted things to his friend’s floating situation. There were enormous bags of bricks in every room, heavy enough to keep Andres down when needed. Andres’s bed was nailed to the ceiling. His sheets and comforter were strapped into place with a big elastic band. A set of bongos and some other drums were attached to the ceiling in one corner.

Mr. and Mrs. Padillo were very friendly, and Andres’s sister, Carmen, had put together party games in the basement rec room. Stomp the balloon! (Sebastian had to wear his blindfold—the sound waves were intense.) Freeze tag! (When Elliott was It, he accidentally froze Willa’s hair for real.)

Back upstairs, everyone had pineapple upside-down cake (of course). Nory and Bax wrote it in their food diaries. Also, cheese-flavored potato chips, barbecue potato chips, ranch-flavored potato chips, regular potato chips, and corn chips.

Then Andres opened presents on the ceiling. He carefully handed the gifts to his parents to put on the kitchen table, but wrapping paper remnants drifted slowly down and landed on the guests.

“Andres, do you live near Lacey Clench?” asked Pepper, removing green ribbon from her hair.

“No, but Rune lives down at the end of my block.”

“Ah, that must be it,” Pepper said. “I saw the Sparkies in a tree house on my way here.”

“Rune has a tree house, all right,” said Elliott. “I used to go there all the time, back when we were friends.” A shadow crossed his face. “Back when I thought we were friends.”

“I used to see you there sometimes, remember?” said Andres. “In ordinary school, before my magic came in, Rune and I hung out all the time, because of how close our houses are.”

“I wonder if they’re plotting against us,” said Nory.

Bax lowered his voice. “We could spy on them,” he ventured. “If we wanted to find out what they’re plotting.”

“You are an evil genius, Bax Kapoor,” Nory said.

Bax flushed with pride.

*  *  *

“The most important thing is stealth,” said Bax, a couple of minutes later. The UDM kids were a few houses down from Rune’s, huddled together and buzzing with nerves. “Nory, you flux into a kitten,” he instructed. Bax’s mom was a detective, after all. She had told him about stakeouts. “No bitten, no mitten, no koat, no dritten, no funny business,” he went on. “Can you do it and stay kitten-shaped?”

Nory nodded. “No bitten, no mitten, no koat, no dritten.”

“Good,” said Bax. “You do that and then climb up the tree and act like an actual kitten. Stay hidden! Andres, you need camouflage. We’re going to decorate you with leaves.”

“Someone still needs to hold my leash,” said Andres.

“I will,” said Willa.

Bax found some leaves and vines to camouflage Andres and Willa. “Now, does anyone want to be shrunk by Marigold? That would be a great detective move.”

“I am not doing that to anyone again,” said Marigold. “I refuse.”

“Okay. It was just an idea,” said Bax. “It could be a really useful talent for police work, you know.”

Marigold smiled.

“Everyone ready?” said Bax. “Nory, flux! Andres, pull that one twig a little farther over your shirt—perfect. Willa, sneak into the bushes and let Andres float up near the tree house. The rest of us will be just around the corner in case you need backup. Go, go, go!”

*  *  *

Nory liked the idea of being a detective on a stakeout. Lots of detectives were Fluxers. She fluxed into an ordinary kitten and climbed as close as she could to Rune’s tree house.

Lacey was holding court. “I was practically trampled four times that day,” she said. “And everyone looked like ugly giants. They were so big.”

“Except really you were small,” said Zinnia. “And also, we’ve heard all this before.”

“Zinnia?” Lacey said sharply. “Watch it.”

Zinnia bowed her head. She sat beside Lacey. On Lacey’s other side sat Rune and two other kids from the fifth-grade Flare class.

They’ve added to their ranks, Girl-Nory thought. Not good.

The talk continued, and this larger group of Sparkies had plenty of negative things to say about all the UDM kids. They said Marigold should be kept home from school because of how dangerous she was. They made fun of Sebastian and how he ducked to avoid the sound waves in gym class. They called Pepper “cruel to animals” and mocked Elliott.

“He tried to roast a marshmallow once, and it just froze into a Popsicle!” Rune laughed. Nory hoped Elliott couldn’t hear him.

“That skunk-elephant girl is disgusting,” said one of the new recruits. “She’s the one who’s really wonko.”

“That’s Nory Horace,” said Zinnia.

“Can she do other wonko shapes? Someone in the lunchroom said something about a mosquito kitten.”

“Gross!”

At that moment, Girl-Nory wanted to try for the driger—dragon-tiger—and show these kids what scary really meant.

But then she’d blow her cover.

And she might burn them.

Or eat them.

She probably couldn’t even do a driger. She didn’t have tiger yet.

So she kept quiet, even though she liked what they said next even less.

“Bax,” Lacey was saying, “is as dumb as a box of rocks.”

“Instead of playing rock, paper, scissors,” Rune went on, “he probably plays rock, rock, rock—and still loses. And then there’s Willa. She rains anytime anyone says boo to her. She’s the biggest crybaby in the world.” He laughed.

Kitten-Nory couldn’t say anything, but she looked down at Willa in the bushes and saw tears running down her face.

Andres was tangled in the tree branches. Nory couldn’t see his expression.

“Enough complaining. Let’s get something done,” Lacey said. “We’ve all signed the petition, but we need to get more people. Too many people are saying no to me. That’s why we have to think about what the worst things those UDM guys could do. Then we need to make them do those things.”

“How?” asked Zinnia.

“By making them mad or teasing them or whatever—and we need to make sure everyone sees. If they mess up in a really big way, people will agree they don’t belong at Dunwiddle.”

“Willa’s an easy target,” one of the new Sparkies said. “The indoor rain does a lot of damage.”

“That Pepper girl can do more than she lets on, I’m sure,” Rune said. “I bet she can force animals to do things for her, out of fear. We could, I don’t know, go to the Fuzzy lab, release all the animals, and then get Pepper to scare them so they wreck stuff.”

“What about Elliott?” Rune said. “He turns stuff to ice. How could we use that? What would be the worst thing we could get him to freeze? How big can he go? Let’s make him do something terrible!”

There was a rustling in the tree. A frantic shaking of branches. “What kind of person are you?” Andres shouted at Rune. “Elliott brought peanut butter cookies up to this very tree house! I was there! You ate them!”

“Andres?” Rune said. Nory saw him look from side to side.

“Yes! Remember me?” He’d totally lost his temper, and the branches were going crazy.

They had to get him out of the tree. Nory leapt down to the sidewalk and fluxed back into a girl. She grabbed Willa’s hand. “Come on!”

“Hey!” Rune called, looking down from the floor of the tree house. “They were spying on us!”

Nory and Willa pulled on Andres’s leash, but Andres was caught in the branches.

They yanked.

Andres yelped.

They yanked again.

Then five Sparkie faces appeared over the walls of the tree house. All five faces were angry.

Nory and Willa yanked again, even harder this time. Finally, Andres came loose from the branches with a crackling of wood. Leaves fell everywhere.

“Run!” he screamed.