“I’m sure the lioness is fine,” said Ben, putting his arm around his sister. “She probably woke up just after we left and has made her way back to the pride.”

“Then why is her signal still in the same place?” Zoe said, trying to hold back tears. “I gave her too much tranquilizer. I should’ve known better. She’ll be at risk from predators now — and that other lion.”

Ben gave her a friendly nudge. “It’s probably your BUG getting it wrong,” he said. “It might still be malfunctioning.”

Zoe managed a half-hearted smile. “That could be it,” she said. “I’m being silly, sorry.”

She went silent as they heard strange wailing sounds fill the air around them. “What’s that?” she said, clutching Ben’s arm. She peered out over the sand. It was dark now. She felt herself shiver. “It’s so creepy, like spooky musical instruments.”

“Ghosts of the Kalahari!” said Ben, his eyes wide.

“Don’t be silly,” said Zoe. “It can’t be.” She paused. “Can it?”

Ben grinned. “Perhaps they’re phantoms of travelers lost in the desert,” he said in a sinister voice. “Searching for their next victims.”

Zoe rolled her eyes.

“Or maybe it’s a bunch of camels playing clarinets?” Ben said.

Zoe punched Ben in the shoulder. “You know what it really is, don’t you?” she said.

Ben grinned at her. “It’s the sand singing!” he said. “I read about it on the plane. It happens here in the desert when the wind has dropped.”

Zoe punched her brother’s arm. “How can the sand make that noise?” she asked.

“The wind drives the sand up the dunes,” Ben said. “But in the end, the top gets too heavy and starts to slide. That’s what we can hear.”

“Weird!” said Zoe. “You wouldn’t expect it to sound so eerie.” She shivered and moved closer to her brother. “The temperature’s dropping.”

She looked out from under the shelter up at the black sky. It was filled with bright stars. “It’s going to be a cold night.”

Ben checked the little cub’s leg wound by under a flashlight’s beam. “His leg looks clean,” he said. “Let’s get some sleep.”

He unfolded their sleeping bags and they curled up as close to each other as they could.

“Jossy makes a nice heating pad,” Zoe said as the little cub lay beside her.

In the distance, she could hear cries of nocturnal creatures calling to each other. She made sure that the scent disperser was still working on her BUG and then analyzed the calls.

“Jackals,” she told Ben. “Leopard and hyenas, too! It’s predator city out there.”

“This could be a problem,” said Ben. “They won’t smell us, but they might catch Jossy’s scent. We need a deterrent.”

“One of us stays awake with the tranquilizer gun?” said Zoe.

“No need!” said Ben. He tapped some keys on his BUG and aimed a hologram image of a crackling fire just beyond their shelter. “That should keep them away.”

Jossy suddenly wriggled and scratched his ear. He looked around, interested in the distant calls.

“Better make sure he doesn’t wander off again,” said Zoe. She took the rope from Ben’s backpack and fastened it round Jossy’s body in a harness, tying the other end firmly to her wrist. “Now if you make a break for it, you’ll be dragging me with you!”

Zoe stroked the cub’s back as he rubbed his cheek against her face. “He’s such a darling,” she said. “I wish I could keep him.” She caught sight of her brother rolling his eyes. “I know, I can’t.” She grinned.

Jossy snuggled down and was soon breathing deeply, his paws twitching as he dreamed. Zoe huddled close to the warm cub. The air on her face was getting very cold. She began to wish that the hologram image of the fire was real.

A while later, Zoe pulled her sleeping bag around her ears. Ben was already asleep, but Zoe couldn’t get comfortable. The creepy song of the sands was still echoing in the distance, and that got her worrying about the lioness again.

Zoe was sure that she had used the correct amount of tranquilizer. Then why hadn’t the signal moved?

As her anxious thoughts whirled around her head, Zoe felt like she’d never fall asleep.

The next thing she knew, Zoe found herself at the top of a sand dune ready to toboggan down toward a huge pool of cool, inviting water. She jumped on her sled and was about to launch herself down when Grandma appeared, grabbed her wrist, and tugged it hard.

Zoe jerked awake. The sky outside their shelter was dashed with orange and purple like it was on fire. She peered at it, puzzled.

“It’s dawn!” she said. She’d been dreaming. Of course Grandma wasn’t here with them. Also, she was thirstier than she’d ever felt in her life.

But something was pulling at her wrist. She hadn’t been dreaming that. She sat up and looked around her. It was Jossy tugging at his leash! The little cub was scampering about at her feet, limping slightly.

The cub nosed the ground, while pawing at a small, dark object.

“You’re feeling better, Jossy,” said Zoe. “That looks like playing to me.”

Zoe gave Ben a nudge. He stirred and gazed blankly at her, his hair sticking up. “What’s going on?” Ben muttered, rubbing his eyes.

“Our patient has recovered,” Zoe said. “He’s playing a game.”

Ben focused on the cub. “What’s he playing with?” he asked as Jossy pounced again.

With dread, Zoe realized what it was. “It’s a scorpion!” she cried. “And it’s about to strike!”