ory Brennan.”

Karsten spat my name as though it were something bitter on his tongue.

I gaped, thunderstruck.

Our bunker was practically invisible. How had Karsten found it?

The boys stared in dejected silence. Game over. We’d lost.

“So this is where you plot your little larcenies.” Karsten smirked, amused by his own wit. “How quaint.”

Karsten’s eyes suddenly widened, then narrowed to slits. I followed his sightline.

To Coop.

The puppy was planted before me, legs splayed, ears flat, fur bristling. His lips were curled, revealing glistening white teeth.

Coop’s eyes stayed on Karsten as a low snarl rose from his throat.

“It’s true.” Karsten’s voice trembled with rage. “You took him.”

“Yes,” I said evenly. “We did.”

I stroked Coop’s head. He remained tense, alert to Karsten’s every move. Ready to strike.

“Who told you to do it?” Karsten glanced about, dropped into a chair. His yellow sneakers were splattered with mud. “Who are you working for?”

“What are you t-talking about, m-man?” Shelton stuttered with nervous agitation. “We d-don’t work for an-anybody!”

“Bullshit!” Karsten’s outburst shocked me. I’d never heard him use profanity. “How did you get through the doors, the locks? Don’t insult my intelligence by claiming you acted alone.”

“Sorry, but it’s the truth.” I crossed my arms. “We weren’t even there for the dog. But when we found him, we had no choice.”

“Then why did you break in? And how did you do it? Tell me everything. Now!”

Seeing no other option, I did.

I explained the mad-bomber monkey. The crusted dog tag. The sonicator. Stumbling upon the secret lab. Discovering the story of Katherine Heaton. Finding the skeleton. Being shot at in the dark.

Karsten was quiet for a very long time. When he spoke again, his voice was calmer.

“You actually found a body?”

“We did,” Ben said.

“Katherine Heaton.” I watched for a reaction. “But gunmen chased us away. On your island.”

Karsten’s eyes went far away.

“Katherine Heaton.” Barely audible. “All my years on Loggerhead, she was there all the time.”

I was surprised. His sadness appeared genuine.

Nevertheless, I pressed.

“You were angry we brought the police. And you have access to monkey bones. That makes you a suspect.”

“Stupid girl!” The acid was back in his voice. “Katherine and I were classmates at St. Andrew’s High. She was a friend, a fellow lover of science.” A bony finger jabbed the air in my direction. “I was devastated by Katherine’s disappearance. Don’t speak of things you know nothing about!”

“I’m sorry.” I was. Karsten’s words rang true. “But someone buried Katherine Heaton on Loggerhead Island. That someone stopped us from revealing that we’d found her remains.”

Karsten’s eyes drifted. For a moment he seemed to debate with himself. Then he refocused.

“I have no idea. Katherine’s death is a very cold case. One unlikely ever to be solved.” Karsten stood. “You children have committed a serious crime. More serious than you know.”

“We’re not the only ones,” Hi shot back. “Your twisted experiment was unauthorized.”

Karsten straightened his glasses. “Is that so?”

“It is. We found proof this afternoon.” I couldn’t help myself. “Did you enjoy the aquarium?”

Karsten stiffened.

I poured it on.

“You don’t list your sick tests on the official register.” I pulled the deposit slip from my pocket. “And you’ve been taking money on the side. How’s that work, Dr. Karsten?”

Karsten’s face went ashen. His hands trembled, curled into fists.

For the first time, I felt fear. Was the man crazy? Desperate? We were alone out there, miles from help.

Instead of lashing out, Karsten removed his glasses and rubbed his eyes. When the thick lenses were repositioned, a different man peered through them.

“You’re right,” he said quietly.

Excuse me?

“My project was secret. Illegal.” He inhaled deeply. Exhaled. “I pray I haven’t caused irreparable damage.”

“Like torturing an innocent puppy?” I demanded.

Karsten glanced at Coop. Coop growled.

“Why’d you do it?” Ben asked.

Karsten shook his head. “You wouldn’t believe me.”

“Try us.”

“To save millions of canines from untimely deaths. To create a cure for parvo, not just a vaccine.” The thin lips drew up in a humorless smile. “And yes, to make a fortune doing it.”

As before, Karsten’s demeanor changed without warning. His fist slammed his palm.

“I took every precaution! That door was supposed to be impenetrable. No one knew of that lab but me.”

“If that was your goal, why not get approval?” Shelton asked. “Why sneak around?”

“I know why.”

Eight eyes shifted to me. I could feel Karsten trying to read my mind.

“Dr. Karsten created a new virus. A dangerous experimental strain. A hybrid of canine parvo and Parvovirus B19.”

Karsten appeared to shrink in on himself. “How could you possibly know that?” he whispered.

“We saw the clipboard by Coop’s enclosure. You infected Coop with something called Parvovirus XPB-19.” I glanced at Shelton and Hi. “Tonight we learned about a human strain called Parvovirus B19. Doesn’t take a genius to do the math.”

Defeated, Karsten didn’t bother to protest.

“The names could be coincidence,” I went on. “But that’s not how I know.”

“Then how?” he asked quietly.

“Because we caught it, Dr. Karsten. We’ve been infected.” I spread my arms wide. “You turned us into Virals.”