Panic rose in Emma’s chest. “Help!” she screamed, but her voice didn’t seem to carry, bouncing off the close, thick walls. “Help!” she cried again, but it was no use. No one called out from the other side. Why weren’t Sutton’s friends back by now? Why didn’t they hear her?

She looked into the wider opening again, pricking up her ears for another one of Gabby’s moans. “Gabby?” she whispered, looking right and left. Her heart pounded so loudly in her head she feared its vibrations might cause another landslide. Her eyes began to play tricks on her, forming shapes she knew weren’t there. A chair. A seated figure. A tennis racket propped up against the rocks. Her head spun; she had to be losing oxygen in the sealed space.

And then a cold, strong hand grasped Emma’s wrist.

Emma screamed out. She tried to wrench free, but the hand wouldn’t let go. The flicker of a dim flashlight illuminated the lower half of a girl’s face. “G-Gabby?” Emma stammered.

The figure in front of her smiled. But those weren’t Gabby’s lips. Emma drew in a breath. Was that . . . ?

“Hi, Sutton,” said the girl, followed by a maniacal giggle. “Glad you could drop in.”

The dank air chilled the back of Emma’s neck. Her free hand dug into dirt and rocks to steady herself. “Lili?” her voice quivered. “W-what are you doing here?” Hadn’t they left her at the Super Stop station? Hadn’t she refused to come?

“Come on, Sutton.” Lili cackled. “You know the answer to that, don’t you?”

The words sliced through Emma’s chest. All at once, she understood what was going on: Gabby and Lili’s fight, Gabby’s fall, Lili’s moans inside this cave, even the walls crumbling down around Emma—all of it had been orchestrated by Gabby and Lili as a way to get Emma in here alone. They weren’t mad at each other. Gabby wasn’t hurt. The Twitter Twins knew Emma would crawl into this cave to rescue the girl she’d thought she’d pushed—because she wasn’t Sutton, because she would feel terrible about what she’d done. And now, they had her right where they wanted her. They had warned Emma, hadn’t they? Countless times, countless ways. Keep being Sutton. Say nothing. Stop sleuthing. I mean it. Or you’re next.

She’d fallen right into their trap.

“Please.” The word spilled from Emma’s lips. Her body bucked and her head spun; she thought she might throw up. “Can’t we talk about this?”

“What’s there to talk about?” Lili asked in a low voice.

“Please let me go,” Emma begged, trying to pull away. Lili gripped her tightly. “I screwed up, Lili. I’m sorry. But I won’t do it again. I promise.”