“Pluggers.”

Daisy screamed. Penny whirled around, aiming her leaf blower upward. But Bernard was gone.

With Daisy and Penny looking skyward, Spencer was the only one who saw a masked face appear in the open tailgate. It was a human rider, dismounted from his giant Toxite so he could fit through the narrow opening. His gloved hands came up, flicking a Glopified mop.

The strings tangled both of Penny’s legs. She pitched forward, dropping her leaf blower and trying to grasp anything. She shouted as the strings retracted, dragging her through the sludge toward the enemy.

Daisy lunged, grabbing Penny’s hands, but she just slid uselessly across the truck floor. Spencer dug the small razor­blade from his pocket and pushed the button. The blade rang out and he dove forward, slicing through the Glopified mop strings.

Daisy and Penny tumbled across the truck. Spencer rocked back on his knees, the razorblade tight in his grasp. With his attack thwarted, the BEM worker ducked out of sight.

“They took Bernard,” Daisy said, staring up at the tear in the truck’s roof.

Then, as if in answer to her statement, the garbologist came hurtling through the snowy opening and landed with a clang not three feet from Spencer.

Bernard was limp and motionless. His body steamed, covered in glowing green slime. Penny scrambled forward, pulling off his headlamp and turning the light on Bernard. Daisy stared in shock, but Spencer had to look away.

“Is he . . .” Daisy swallowed. “You know, D-E-A-D?”

“He’s going to be in a minute,” Penny said. Her hands were passing over Bernard, carefully stripping back his dissolving clothing and checking his pulse. Oozing burns covered his shoulders and neck.

“What did they do to him?” Daisy asked.

“Grime slime,” answered Spencer. He recognized the glowing gunk from the parking garage below New Forest Academy. The enlarged Grimes had the capability of filling their throats with poisonous slime. “It spat on him.”

Daisy gulped. “I don’t think his arm is supposed to bend that way.” Spencer made the mistake of looking. It was like Bernard had two elbows in one arm.

“Yeah,” Penny said. “His arm’s busted. I think he’s got a concussion, too.”

Penny’s hand went to her waist. Spencer hadn’t noticed before, but there was a set of spray bottles dangling from her janitor belt. Seeing them reminded him of the terrifying vision of Mr. Clean, unstoppable with such weapons.

Penny unclipped one of the bottles and flashed her headlamp across it. A bright orange liquid sloshed about halfway up the bottle. Penny adjusted the spray nozzle and pointed it at Bernard’s neck. Giving a few sprays, she misted the entire wounded area. Immediately, it began to foam and bubble, filling the garbage truck with the clean scent of citrus.

“My dad says we’re not supposed to spray people with cleaning liquids,” Daisy said. “My cousins did it one time and they got nasty rashes.”

Ignoring Daisy’s warning, Penny carefully removed Bernard’s aviator cap. There was a deep gash in his scalp, streaking his short dark hair with red. Penny squirted the cut from one end to the other until the entire gash had foamed over.

“What is that stuff?” Spencer asked.

But Penny was too focused on first aid to talk. She moved on to Bernard’s broken arm. Spencer couldn’t watch as she tugged away the sleeve. He heard the distinct spray of the bottle, and then Penny sighed.

“It’s an all-purpose cleaning solution,” Penny said, “with peroxide.” She turned the headlamp back to Bernard’s neck. The foamy cleaner was receding from his shoulder, leaving the skin pink and fresh, as if it had never been burned.

“And it’s a healing spray,” Penny said. She clipped the bottle back onto her belt. “It’s a race now.”

“Relay race, or normal race?” Daisy asked. “Or three-legged race? I’m good at those.”

“A life-and-death race,” Penny said. “If his wounds kill him before the cleaning solution takes effect, then there’s nothing we can do. Twenty . . . thirty minutes, and we’ll know.”

Penny rose to her feet. “You two stay with him. If he wakes up, try to get him talking.” She headed for the open tailgate.

“Where are you going?” Spencer asked. “They might still be out there!”

“That’s what I intend to find out.” Penny dropped through the opening and out of sight.

Spencer and Daisy turned back to Bernard. They didn’t dare say anything, as if speaking of death might bring it closer. They simply watched the garbologist, prone on the floor of his garbage truck, covered in foamy, citrus-smelling, all-purpose cleaning solution. His chest rose and fell with labored breaths, and the rhythm of it seemed to put the two kids into a worried reverie.

They had no idea how much time had passed before Penny returned. The agile young woman boosted herself into the back of the truck, something dangling from her hand.

“They’re gone,” Penny said. “But I found this.” She held out the object, illuminating it with her headlamp. Spencer recognized it immediately as the extension cord he had severed with the razorblade. It was still attached to the battery pack the rider had strapped around his waist.

“Is that what they use to ride the Toxites?” Daisy asked.

“Looks like it.” Penny crouched next to the kids to inspect the battery pack. There was a dial in the center with a little blinking yellow light. When Penny turned the dial left, the exposed end of the extension cord sparked and the blinking light turned green. Penny twisted the dial the other direction. The electricity decreased and the light turned from yellow to amber to red.

“The dial regulates the flow of Glopified electricity,” Penny said.

“That’s how they control them,” Spencer said. “Remember the cords at New Forest Academy? When the Toxites were plugged in, they were calm. They like the electricity because it makes them grow.”

“So,” Penny said, turning the dial back to green and increasing the electricity, “the Toxite won’t go anywhere if it’s on green. Like parking your car.”

“But if you turn it to yellow, the Toxite starts getting angry. It realizes that it’s relocated and wants to attack.”

“I don’t even want to imagine what happens if you turn it to red,” Daisy said.

“Closer to red means less electricity,” Penny summed up. “Less electricity means angrier Toxites.” Penny blew a strand of red hair from her face. “This is bad. The BEM has a huge advantage with these . . . these Toxite-riders.”

“Pluggers,” Spencer said. That was what Mr. Clean had called them when he rescued Leslie from prison. “The BEM calls the overgrown monsters Extension Toxites. The riders are called Pluggers. ”

“You’ve seen them before?” Penny asked.

Spencer nodded. “In a vision. Mr. Clean used an Exten­sion Filth to rescue Leslie Sharmelle from prison. She’s a Plugger now.”

Penny pointed outside. “That was your old substitute teacher out there?”

Spencer shook his head. “I didn’t see Leslie tonight. But there’s a whole gang of Pluggers under her command,” he said. “Mr. Clean sent them on a manhunt to find my dad.”

“Maybe that’s why they left,” Daisy said. “They realized that Alan wasn’t with us.”

“But why were they here in the first place?” Penny said. “They followed me into the bus depot.”

Bernard suddenly sat bolt upright, causing everyone else to jump back in surprise. “Which way did they go!” he shouted. “Where are they?”

“Relax.” Penny put a hand on his knee. “It’s all right, it’s just us. They’re long gone by now.”

Bernard closed his eyes in misery, and for a moment Spencer thought he might see the grown man cry. “They took the package!”