“Potato, potahto.”

Spencer thought it was strange to watch the sun set through the windows of an elementary school. Stranger still to know that he would probably see it rise through the same window.

The team had made camp inside Woodbury Elementary School, about two hours south of Triton Charter. The janitor at Woodbury was a friend of Walter’s and a highly trusted Rebel. He had let them into the school as soon as the students had gone home.

The Rebel team members had made themselves comfortable in the janitor’s closet, while Spencer and Daisy were led to the gym so they could finally shower off the crusty spaghetti sauce.

The Woodbury janitor brought them dinner and gave Walter instructions on how to lock the school. Then he departed, leaving the team alone as the sun set.

“How does it feel to have your dad back?” Daisy asked, coming alongside Spencer in the dim hallway.

He shrugged. “Not all that different from when he was gone.”

“But he saved you from the principal’s office,” Daisy said. “That’s got to feel good.”

“He chewed me out.” Spencer looked at his feet. “He didn’t even say hello.”

“He was just pretending.” Daisy paused. “Right?”

Footsteps in the hallway caused them both to turn. It was Walter, both hands in his pockets. “We’re ready to begin,” Walter said. “Your dad has inspected the package for traps and safeguards. The time has come to open it.”

Spencer and Daisy followed Walter into the janitor’s closet. It was larger than usual, with a round table in the middle of the room. Bernard and Penny were already seated. Alan stood, the package resting in his hands. Spencer, Daisy, and Walter took the three remaining chairs.

A reverential hush settled over the janitor’s closet. Alan looked briefly at each member of the team. It was as though he were making a last-minute decision whether to let them see the contents of the package. Then his eyes turned to the white mailing tube in his hands.

“Let me start at the beginning.” Alan’s tone was dark and somber. “Back when there were two of us.” His brow wrinkled at a bitter memory. “Did any of you ever have the pleasure of meeting Rodney Grush?”

Alan looked around the table, but all heads were shaking no. Spencer had heard the name a hundred times. Rod Grush was his dad’s science partner. For a long time, Alice had blamed Rod for Alan’s sudden disappearance.

“Rod was my friend and colleague. We worked together at Winowah Junior High School in Washington. He taught chemistry and I taught biology. We were both heavily involved in the science division for the Bureau of Educational Maintenance.”

“You worked for the BEM?” Daisy asked.

“Back when they were good,” Alan answered. “About three years ago, the BEM approached us, asking Rod and me to head up a top secret mission. The warlocks had discovered a clue. Something that would lead us to the source of all Glop.”

“What’s so important about the source?” Penny asked.

“The source is where it all began.” Alan’s face flushed with the importance of what he was about to say. “Toxites are born from Glop.”

There was a moment of thoughtful silence, and then Bernard raised his hand. “So you mean to tell me,” he said, “that there’s no such thing as mommy and daddy Toxites? The little creatures just pop out of the Glop on their own?”

“Exactly,” Alan said.

“No parents?” Daisy said. “Sad for them.”

Walter’s face was more intent than Spencer had ever seen it. He obviously understood the magnitude of Alan’s discovery. “This changes everything,” the warlock said.

“Indeed it does,” Alan said. “If Toxites are born in Glop, then we finally know how to get rid of them permanently.”

“Find the source of Glop and destroy it,” Walter finished.

It was quiet again, and then Spencer spoke up. “But if we destroy Glop, there wouldn’t be any more magical supplies.”

“We wouldn’t need magical supplies,” his dad said. “There would be no more Toxites to fight.”

A life without Toxites. It was indeed a wild idea.

“But no one knows where Glop originated,” Walter said. “How did you expect to find it?”

“We were looking for help from the only people who know how to find it.” Alan turned to Spencer. “We were looking for the Aurans.”

Spencer felt all eyes shift to him. He cowered in his seat, feeling his face turn hot from the unwanted attention. “I don’t . . .” he said, head shaking. “I don’t know how to find the source of Glop.”

“The other Aurans,” Alan clarified. “The original thirteen. They will tell us how to find the source.”

“The Aurans don’t speak to us,” Walter said. “Few warlocks have ever even seen them. Most of the time the Glop is delivered during the night. I awake to find it at the foot of my bed.”

“Sounds like they’re in league with the tooth fairy,” Daisy interjected.

Walter continued, ignoring the girl’s comment. “We don’t even know how to find the Aurans, let alone get them to divulge the location of the source.”

“Maybe we can use Spencer,” Penny said. “If we could find a way to reveal that he’s an Auran, maybe it would lure the original thirteen out to find him.”

“No.” Alan shook his head. “We must keep Spencer’s status secret for as long as possible. That means we don’t mention a word of it to anyone outside this room. Can we agree on that?” Alan looked around the room, accepting either a verbal “yes” or a head nod from everyone at the table.

The attention bothered Spencer. Why did his dad have to treat him like he was a dangerous secret? Spencer wondered if his dad would take such an interest in him if he weren’t an Auran.

“There is a way,” Alan continued. “A way to find the Aurans and gain their cooperation that doesn’t involve putting Spencer at risk. That’s the secret mission that Rod and I were supposed to accomplish. The BEM gave us a clue, the first in a sequence of thirteen. It took Rod and me the better part of a year to solve the first twelve clues.” Alan paused, brushing his hand over his eyes. “We passed through our fair share of dangers and difficulties, and I learned to trust Rod Grush with my life. It was late August when we found the final, thirteenth clue. Dallas, Texas. At an intermediate school.

“Rod and I broke into the principal’s office late one night. Following instructions from the previous clue, we began peeling back a strip of carpet in the corner. There was noise in the hallway, and before we knew it, we were under attack. We didn’t know who it was, but they were armed with Glopified weapons and wore the seal of the BEM.

“We locked ourselves into the principal’s office, but it was clear that the door wouldn’t hold for long. I returned to the corner, frantically tearing up floorboards. But Rod . . .” Alan swallowed hard. “Rod went out to buy me time. His surprise attack was so sudden that he drove them down the hallway, giving me time to find this under the floorboards.”

Alan tipped the mailing tube, and something slid out of the package. It was a shiny metal cylinder, about an inch wide and just under a foot long. There was a black cap at one end, held in place by a metal clasp. Alan held up the cylinder so the whole team could see the number 13 written in dripping red paint.

“The BEM workers were returning, and I had no time,” said Alan. “It was a matter of minutes before they captured me. I couldn’t let the cylinder fall into their hands. I couldn’t let them steal what I’d worked for. I found the mailing tube and stamps in the principal’s desk. I’d seen a secure mailbox just outside the office, so I made a run for it. The attackers didn’t see me slip the package through the opening, but before I could get away, they were onto me.”

He looked down for a moment, taking deep, steadying breaths. “They dragged me outside. Rod was on the steps of the school, tangled in mop strings. One of them tied my hands, and I heard him say, ‘We’ll leave this one alive for questioning.’ That was when I knew that Rod Grush was already dead.” Alan paused, giving his old friend a moment of respectful silence.

“I was sent to a BEM compound and questioned for a year and a half. Then, as if I wasn’t miserable enough, they threw me into a dumpster for six months. I hadn’t opened the cylinder, so I could tell them nothing. Only two words escaped my lips: Spencer. Son.” He looked at his boy. “I had mailed the package to Spencer, where it sat untouched for over two years. Now it is found. And we’re here to open it.” He held up the silver cylinder.

“What happens when we solve the last clue?” Daisy pointed to the cylinder in Alan’s hand.

“This clue should direct us to a map. The map will lead us to a hidden landfill. That is where we’ll meet the Aurans.”

“The Aurans live at a landfill?” Spencer raised his eyebrows, not so sure if he wanted to be associated with kids who’d been living in a trash heap for a few hundred years.

“What makes you think the Aurans will cooperate once we find them?” Penny asked.

“They left the clues for someone to solve. I think the Aurans want to be found. Maybe this is their very purpose. Maybe the Founding Witches left them here so that whoever solved the clues could put an end to Glop and Toxites forever.”

“If the Aurans are hundreds of years old,” Penny said, “then how come that cylinder looks so new and shiny?”

“The Aurans periodically updated the thirteen clues, keeping with the times as technology advanced,” Alan said. “I have learned never to underestimate the Aurans. They want to make it as difficult as humanly possible to find the map to their landfill. We have to earn the right to speak with them.”

“Mmm, landfill . . .” Bernard said, a grin spreading across his face. “So there’s gonna be garbage?”

“Lots of garbage,” said Alan. “Which is why I put you on the team.”

Bernard rubbed his hands together in pure joy. “I love a good dump.”

“It’s not a dump,” Penny cut in. “It’s a landfill.”

“Dump, landfill. Potato, potahto.” Bernard shrugged. “Same dif.”

“No,” Penny persisted. “A dump is not a landfill. I did a report on it in high school. There’s a big difference.”

“No difference,” Bernard said stubbornly. “Place for garbage.”

Penny leaned across the table. “Dumps aren’t even legal anymore. Once upon a time, people heaped their hazardous waste into holes in the ground and called it good. Now we have landfills—well-engineered disposal sites for nonhazardous solids.”

“Bern! Penny!” Walter finally cut in. “Can you have this discussion later?”

“Same thing.” The garbologist sat back, smiling as he managed to sneak in the final word.

“Let’s suppose we find the Aurans and they tell us the location of the Glop source,” Walter mused. “How do you plan to destroy it?”

Alan had an answer ready. “The Aurans have been destroying Glop for centuries. They collect old maxed-out Glopified supplies. Somehow they extract the Glop, deliver a small portion back to the warlocks, and destroy the rest.”

Penny sat forward, a scheming look in her eye. “If we can find out what the Aurans use to destroy the Glop, then we might be able to use the same method to destroy the source.”

“I think we’re getting ahead of ourselves,” Bernard said. “We’ve got to find the map to the dump first.”

“Which is why we have this.” Alan hefted the cylinder and took a deep breath. “Let’s find out what’s inside.”

His thumb flipped the clasp, and the black lid sprang open.