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.