Turning on each other

Sun Wei strode forward and pulled the second copy from the shelf. But the moment he flipped it open, his lips curled into a smirk.

The pages had been hollowed out. Inside the carved-out space, nestled neatly in the center, was a bronze key.

He plucked it out effortlessly, holding it up between his fingers. "Got one."

His eyes scanned the room, landing on Chen Lin, who stood near a row of bookshelves, her arms crossed and brows drawn together in deep thought. Unlike Zhao Ke, who was still actively searching, she hadn't moved much since picking her clue.

Curious, he strolled over.

"Stuck?" he asked, his tone light but laced with amusement.

Chen Lin huffed but didn't look at him. "No. Just thinking."

Sun Wei glanced at the clue in her hand.

"The missing number is the key," he read out loud, and he cant help but say, "You picked a hard one." 

Chen Lin nodded at first, then shook her head.