Jake kicked off his sneakers, tied the laces together, and slung them over one shoulder. He rolled up his pants legs and waded into the water.

Gemma kicked off her shoes too and followed him in. The water was the temperature of a kiddie pool after someone had peed in it. It smelled a little like pee, too, and Gemma knew that was just because of all the decay, the singed plant life and dead bugs and the fish. The footing was silt-soft and slippery. Jake had told her last night that there were alligators in the marshes, and cottonmouth snakes, too. Gemma prayed they wouldn’t encounter any.

The going was very slow. Jake held his phone high to keep it out of the water and directed the replicas which way to point the kayak. In places Gemma and Jake managed to stick to the shallows, where the water was only shin-deep, and move more quickly, but often the water was waist high or deeper and it was like a huge, outstretched hand was halting their progress. They slogged forward as the replicas drifted behind them, scanning the sky for helicopters. The sun rose and soon they could hear the noise of boat traffic, and see it in the miniature waves kicked up in the water by the boats’ distant passage. Gemma had never known you could be in the water and sweaty at the same time, but she was both, and dizzy from the heat and the effort and the fear. Her lungs felt like they’d been strapped and squeezed into too-tight leather, like they might burst at any second.

“I can’t go on,” she said. She could barely get the words out. “I need to rest.”

Jake turned around as if he was going to object. But one look at her and he just nodded. She must look horrible, red-faced, sweaty, soaked up to her pits. But she was too exhausted to care.

They sloshed up onto solid ground again. Gemma wished Mrs. Coralee, her stupid gym teacher, could see her now. Wilderness Gemma. In the past twelve hours she’d paddled a kayak and hiked nearly two miles through a slog of swamp. She’d probably keel over and die of shock.

Gemma’s legs were shaking, and she sat down immediately in the mud. The replicas followed, disembarking clumsily from the kayak. Jake helped them drag it up beneath the shade of a mangrove, and not a second too soon.

“Get down,” Jake said hoarsely. They crouched together, shaded by the network of moss-fuzzed branches, while a roar grew steadily above them and the water splintered into waves. Then a helicopter swept overhead, so close it drove the dirt up into Gemma’s eyes and stripped the leaves from several branches. But they hadn’t been spotted. That she was sure of. Luck.

Jake stood up. She could read the tension in his whole body, in the set of his jaw and shoulders. “I think we can make it back to the car overland from here,” he said. “We can’t be far. Can you walk?”

Gemma nodded, even though her thighs ached and she was desperately thirsty.

“We’ll have to leave the kayak,” Jake said. “Dragging it will slow us down.”

“You’ll lose your deposit,” Gemma said stupidly. She was so tired she could think only that they’d get in trouble with the rental shop.

Jake helped Gemma to her feet again but tightened his hand on her wrist to keep her from pulling away. “Gemma, I want you to understand something. We’re in very big trouble.” He spoke in a low voice, so the replicas wouldn’t hear, and he kept his tone neutral, pleasant, even, as if they were just discussing the weather. “The people running Haven are very powerful. They’re going to be extremely unhappy that two of their experiments are walking free. They’re going to be tracking us. They might already be tracking us. I need you to understand that.”

“We can’t just leave them on the marshes,” Gemma whispered back. Over Jake’s shoulder, she could see the girl watching her. The fuzz of brown hair cropped so close to her head made her look like a baby bird. Gemma looked away, lowering her voice further. “They’re half-starved. They could have been abused, for all we know. You heard what she said about not being human. Who the hell taught her that stuff?” Gemma thought of her father grinning proudly in front of Haven and felt nauseous all over again. “Besides, the girl is sick or something. Take a look at her.”

“That’s another thing,” Jake said. His eyes were so dark they seemed expressionless. “We don’t know what’s been done to them. They could be carrying diseases.”

“Carrying diseases?” Gemma repeated. She pulled away from him. She was still shaking. “You make them sound like animals.”

“Gemma, think about it.” He caught her arm again before she could turn away. “We don’t know what they were doing in Haven. They weren’t making clones for the glory of it.” So he’d already come to the same realization that Gemma had: If Haven’s goal had been to successfully clone a human being, why all the secrecy? “They could be testing toxins, or studying smallpox. The point is, we don’t know what they were doing.”

Gemma knew he was right. But she saw no other way of getting at the truth. And she was angry—angry because he wasn’t meeting her eyes, because he acted as if it was painful even to touch her now. She turned away from him. “This is what you said you wanted,” she said. “Your father spent his life studying Haven and now, now that you have the chance to know, you’re too scared.”

“Of course I’m scared,” he said quietly. “They killed my father, remember?”

Now, on top of her anger, she felt guilty—which just made her even angrier.

“I’ll take them back on my own, then,” she said. It was ridiculous: she would never find her way back. “I don’t care what you do. You have your answers. You finished your little quest.” She knew she was being unfair, but she couldn’t stop. She was dizzy, and so damn thirsty, too. “Come on,” she said, a little louder, to the replicas, who were standing there looking uncertain. Even Gemma was surprised by how harsh her voice sounded. The boy looked startled, then sheepish, and, perversely, she felt a rush of pride: she’d scared him, the big baddie with the knife.