Miss Blinx dropped me on my tail. Tank Wrenchlin, my best friend and detective partner, lifted me to my feet.

“That was close,” she said. “Rizzo’s battle bot could have smushed you!”

“You said I needed to get close!” I said.

“There’s close and then there’s too close, Fizz.”

“Well, I’m not getting that close to Rizzo’s battle bot ever again.” I handed her the small metal ball she had given me only a few minutes ago. “You can take your code smeller back.”

“It’s a code sniffer, Fizz.” Tank was the best troll tinkerer this side of the Dark Depths. Inside the ball were gears, circuits and a bunch of other stuff I didn’t understand. But Tank did, and that was all that mattered. She inspected the ball for damage. “And I didn’t tell you to nearly get stuck to the battle bot’s foot. We’re trying to solve a case, not turn you into goblin pancakes.”

Solving a case was the reason I’d gotten into that battle in the first place. No one ever said being a detective would be easy. I just wished they would remind me to wear a helmet once in a while.

The whole mess had started two days earlier, when the Troll Patrol cornered us on our way home from school. Thankfully, they didn’t patrol for unfinished homework, or I would have been rounded up a lot earlier. The three grade-eight trolls were Gravelmuck Elementary’s champion battle-bot team. They were also our school’s best chance at winning this year’s Battle Bot Cup. That is, if everyone played fairly.

“Rizzo Rawlins is a cheat,” said the tallest of the three trolls. His name was Daztan. He was the Troll Patrol captain.

“And the Tuesday lunch special is a health hazard,” I said. “Tell us something we don’t know, Daztan.”

I’m normally not so snarky to older monsters. But I had a serious video-game session and a fresh batch of choco-slug cookies waiting for me at home. It’s never a good idea to get between me and my video games.

“Rizzo Rawlins has put together his own battle-bot team to compete in the school finals,” said Ryla, the smallest of the three trolls. She was the coder of the group. It was her computer code that made the Troll Patrol’s battle bots the best in the school.

“But Rizzo is only in fourth grade,” Tank said. “How can he compete with you older monsters?”

“Rizzo gets whatever Rizzo wants,” said Zarkof. He was smaller than Daztan but larger than Ryla, and had bright-orange hair spiked up to look like he’d been electrocuted. “Rizzo convinced Principal Weaver to let him compete, and then he hired some of the other kids in our class to build him a battle bot.”

“Normally, we would be able to defeat any bot they could scrape together,” Daztan said.

“We’ve watched his bot in battle,” Zarkof said. “We think he is cheating.”

“Word on the playground is that you two are detectives,” said Zarkof.

“Best in the school,” Tank said with a smile.

“Good,” Daztan said. “We want to hire you.”

Thoughts of cookies and video games vanished from my detective brain. I was always interested in a new case. But still, I had my doubts.

“Everyone knows Rizzo Rawlins is a cheat,” I said. “How can we prove he’s cheating in the battle-bot competition?”

The flat piece of vizpaper in Zarkof ’s large hands sparked to life. The paper’s surface glowed softly with the words Rockfall Battle Bot Association: Rules and Regulations. Zarkof thumbed through the manual. He cleared his throat before speaking.

“It states clearly in Section 12, Subsection D, that all essential mainframe apparatuses and sub-linear underlying frameworks must be—”

“Um, run that one by me again,” I said.

“Certainly.” Zarkof smiled. “It states clearly in Section 12—”

Daztan stepped in to translate. “What he means is, we have to build our battle bots using parts we make ourselves.”

“And run the bots using computer code that we write ourselves,” Ryla added. “That way, participants can’t just buy the best equipment or hire some professional computer coder to make their battle bot.”

“And that’s what you think Rizzo has done?”

Daztan nodded. “His bot moves too fast. It’s too smart to have been created by a bunch of monsters from elementary school. We think he got his battle-bot parts and code from a professional bot maker. And we want you to prove it.”

“It is quite important that the truth be known,” Zarkof said. “The winner of our school battle-bot tournament will represent Gravelmuck in the Slick City Battle Bot Cup next week.”

“And you think Rizzo will win?” Tank asked.

“If he does win, he won’t deserve it,” Ryla said.

“We just want things to be fair,” Daztan said. “All the other monsters have been working on their battle bots for a long time. It’s not right for Rizzo to use his money to get an advantage over us.”

“If you can prove he bought his computer parts, Principal Weaver will have to remove him from the tournament.”

“A chance to prove Rizzo Rawlins is a cheat?” I looked to my detective partner. Tank’s ears stood at attention like a pair of hungry flame hounds. She was in.