They settled into a circle, facing each other. Mr. Chu appeared to be gaining his strength back with every passing minute, though his hands shook with apparent fear; a small drip of drool crawled down his chin. No one said a word, a silent understanding hanging in the air that Mr. Chu would tell them what was going on when he was good and ready.

“It was terrible,” he finally whispered, barely audible.

“What was?” Sofia asked. Tick cringed; it seemed like a really bad time for her usual impatience.

Mr. Chu continued to stare at the ground in front of him. “These men . . . with some kind of electricity weapon, kidnapped me and took me to a place that was like the barracks of a battleship—metallic and cold. They . . . did things to me. . . . Unspeakable things.” He quit talking.

“Who were they?” Tick asked. His mind couldn’t settle on any possible reason someone might want to take Mr. Chu, who was one of the nicest people Tick knew.

“It was . . . him.” Mr. Chu squeezed his eyes closed as if in pain.

“Him?” Paul asked. “Who’s him?”

“The other me. The bad me.”

Tick felt his breath catch in his throat. An Alterant Mr. Chu?

Tick looked at Sofia; she mouthed the word psycho. A storm of anger surged inside Tick. His face flushed hot, and for the first time since he’d known her, he wanted to scream in fury at Sofia. This was one of his favorite people she was talking about. He was just about to say something nasty when Mr. Chu unexpectedly shot up from the ground to his feet.

“Did you hear that?” he whispered, twisting and turning, searching the surrounding forest.

Tick stood, as did Paul and Sofia, the three of them looking for any sign of what had alarmed the teacher.

“Did you hear that?” Mr. Chu repeated.

“No,” Tick answered. “What was it?”

“Something’s out there. What was I thinking? What was I thinking!” Yelling the last word, Mr. Chu knelt down beside his leather satchel and opened it up, rummaging inside before pulling out three strange objects. “They followed me here. How could I be such an idiot?”

As Mr. Chu got back to his feet, Tick finally heard it. Coming from deeper in the woods, it sounded like hundreds of spinning circular saws, sharp and shrill, accompanied by the horrible crunching and breaking of trees, as if King Kong himself were trampling through the forest with the world’s largest electric razor buzzing at full speed.

“What the heck is that?” Paul asked, a look of alarm spreading across his face that Tick thought must surely mirror his own.

Sofia took a few steps toward the sound, rising onto her tiptoes and tilting her head as if that would help her hear better. “That doesn’t sound good,” she finally said.

Paul rolled his eyes and stomped his foot, clearly impatient to be away from this place. Tick felt a thick veil of creepiness hanging over him.

“They let me go; they let me go,” Mr. Chu murmured, handling the objects he’d pulled from his bag. Tick got a good look at them for the first time, but had no clue what they were. All he could see were a bunch of cloth straps and pieces of dull metal.

“They let me go. . . . They knew I’d come to you. I’m such an idiot! Atticus, I’m so sorry.”

Something was wrong about the whole situation, and Tick knew it wasn’t just the rush of ominous sounds that were growing louder by the second, filling the air with horrible screeches of metal and the splintering crack of wood. Nor was it just the overall strangeness of Mr. Chu’s sudden appearance. Something was wrong, out of place—but Tick couldn’t pinpoint it exactly.

“Shouldn’t we get out of here?” Paul said.

“Won’t do any good,” Mr. Chu replied, stepping close to Tick. He stretched out one of the things in his hands, two strips of cloth attached to a circular ring of metal in the middle. “Until we get these on you, they’ll follow you wherever you go, until you’re dead.”

Mr. Chu grabbed Tick’s right arm and started wrapping the cloth strips around his bicep. Tick was so stunned by the odd situation that he didn’t move or resist. In a matter of seconds, Mr. Chu had snapped the metal ring around Tick’s elbow, and wrapped the attached strips of cloth, like sticky gauze, in candy-cane fashion down the length of his entire arm.

“What . . . what are you doing? What is this thing?” A sick, uneasy feeling spread through Tick and he started to sweat.

“Yeah, what is that?” Sofia asked.

“You all have to put them on,” Mr. Chu answered.

But when he stepped toward Sofia, she swiped his arms away and held up her fists. “You aren’t touching me, you crazy old man.”

The sounds—the spinning saws, the crunching and crashing of trees, a mechanical roar that sounded like something out of an old sci-fi movie—it was all coming very close, very fast. Though Tick couldn’t see anything yet, he could feel whatever was approaching, as if it were pushing the very air away as it rushed through the woods.

Mr. Chu tried again to wrap his gadget around Sofia’s arm, but she swatted him away, then actually swung a fist at his face, barely missing. “I said, stay away!” she screamed at him.

Mr. Chu turned toward Tick, his face intense. “Atticus, I’ve known you and your family for a long time. I taught your sister, I taught you. We’re friends, are we not?”

“Yeah.” Tick looked at Sofia, then Paul. His head swam in confusion. How could this be happening? Why did he feel so . . . wrong? Was this a dream?

“They’ll be here in seconds. If we put these devices on our arms, they won’t see us. Do you hear me?”

Tick didn’t say anything.

“Just wink us away again!” Paul said. “You can do it, Tick. Concentrate and wink us away. Forget this dude.”

“Give me a break,” Tick said. “I have no clue how I did that.”

“Just try,” Sofia said in a calm voice, as if she were trying to talk someone out of jumping off a skyscraper. Tick barely heard her over the mechanical chorus of horrible sounds.

“Atticus!” Mr. Chu yelled. “We have only seconds left! They . . . are going . . . to eat us . . . alive!” He pointed toward the sounds with every pause, his voice filled with fire.

“Just do it!” Tick finally said. “Sofia, just let him do it!”