Excerpt from Do Not Become Alarmed by Maile Meloy, plus links to reviews, author biography & more

"Are you scared, Penny?" she asked.

"No," Penny lied.

"Because they're going to find us?"

"Yes," Penny said. She helped June pull up her swimsuit straps and felt very grown-up. Isabel might be the oldest girl, but Penny was the one June knew and trusted. Her mother had told her to keep an eye on Sebastian and she had, but she hadn't known this would happen.

"I'm hungry," June said.

"We can go back to the buffet on the ship," Penny said. "When they find us."

They rejoined the group, and Hector announced, "I'm going to swim back."

"You can't swim against the river," Marcus said.

"I can," he said. "If I stay to the sides. Where the water goes the other direction."

Penny had been whitewater rafting with her grandparents. "You mean in the eddies," she said.

Isabel said something protesting.

"I'll come back for you," Hector said. He waded out, lowered his body in near the bank, and started swimming. He was very strong. His arms slashed through the water. They watched in silence as he disappeared around a bend. Then they were alone.

"We should be on the other side of the river," Marcus said.

"We can't get up that bank," Penny said.

They studied the other side of the river and the steep mud bank. And then the bank moved. At least it seemed to move. There were tangled roots, and a section of the mottled mud was sliding.

"Oh!" Penny said.

Isabel said something under her breath.

It was not mud sliding, but an enormous crocodile, sunning itself on the bank. It had moved its big sinister head, split by a row of teeth, but now it settled again, motionless.

Isabel put a hand over her mouth.

"Hector will be okay," Marcus said.

Sebastian and June weren't paying attention. They had started making a small mud castle in the soft ground. No one said anything more to alarm them. Penny imagined her mother picking her way through the trees on the opposite bank and coming across that monster. They had to get back before that happened. But there was no reason crocodiles wouldn't be on this side of the river, too. Penny stepped backward. She wanted to get away from the water, away from the muddy banks.

Isabel put a hand over her mouth.

"Hector will be okay," Marcus said.

Sebastian and June weren't paying attention. They had started making a small mud castle in the soft ground. No one said anything more to alarm them. Penny imagined her mother picking her way through the trees on the opposite bank and coming across that monster. They had to get back before that happened. But there was no reason crocodiles wouldn't be on this side of the river, too. Penny stepped backward. She wanted to get away from the water, away from the muddy banks.

In the trees behind them, they heard an engine noise, and turned.

"There's a road!" Penny said. She started toward it.

"We have to stay here," Isabel said. "And wait for Hector."

"We should find the road," Penny said.

They looked at each other. A battle of wills. Penny had read the phrase in books and knew that this was what it meant. Isabel was older. But Penny was smarter. She could not say in front of the little ones that they might be eaten by a crocodile if they stayed here, but she beamed the argument into Isabel's eyes.

"I'm hungry," Sebastian said.

"Me too," June said.

Penny thought of how her mother would panic when she saw they were gone. Sebastian needed food or his blood sugar would drop, but he also needed insulin or his blood sugar might go too high. And he didn't have his pump.

Marcus said they should hang the inner tubes on a branch, to show where they had left the river. Isabel clearly wasn't happy about the plan, but she didn't want to stay alone, so the five of them set off into the dense forest. The crocodile on the other bank hadn't moved again. Hector would be fine, Penny told herself.

Excerpted from Do Not Become Alarmed by Maile Meloy. Copyright © 2017 by Maile Meloy. Excerpted by permission of Riverhead Books. All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.