And now Coll heard it – a deep rumbling sound was coming from the mouth of the channel, from inside the hill. First quiet, then loud, so loud he could hardly think.
“I think we should move back—” he had time to say, before he couldn’t even hear his own shouting voice, and something glinted at the back of the tunnel, a white frothing wall—
And the cave exploded.
Coll scrambled away, falling and landing on his back with an oof! and staring as the silver white wall exploded out of the cave. It crashed along the channel, and he realised in astonishment that it was…
Water.
A huge wall of water, more than Coll had ever seen, was charging like a Construct at full speed towards them and then past them along the channel, spitting and frothing, into the mouth of the opposite cave. It was so loud the sound itself felt like a physical force, shoving him back. The air filled with white mist and the ground under his feet turned instantly dark, the sand like mud, the glass slick and green.
“Whoo-hoo!” shouted Dolen. He lifted his arms, facing into the spray of water, and Fillan did the same.
“Whoo!”
The channel became a river. It was dirty at first, but after a few seconds it ran clear and the pressure eased a little, and Dolen and Namir began refilling their canisters.
“You should do the same,” said Dolen. “It runs for thirty minutes, so take your fill.”
Rieka was already digging out containers and barrels from Cub’s storage, and Coll ran to help. They quickly filled everything they had with clear, pure water. Dolen brought out armfuls of dirty clothes and started soaking them and beating them against the steel sides, and Namir took a brush and washed Beetle.
It was like new life after the horrible desert. Rieka let the water soak her, her eyes closed as she rubbed her face. Brann and Fillan flicked spray at each other, laughing, then scrubbed the grime from Kevin’s joints. The Ant stretched its back in happiness and shook itself dry in a scatter of drops.
Coll became aware of how dirty he felt. Dust and sand clogged his hair and stuck to the sweat on his face and was ground between his teeth. He leaned over the channel and ducked his head into the river, scrubbing his face and hair and letting the current carry away all the desert filth. Pulling out, he hesitated, glanced around, and then unfastened his arm. He rested it on the side and ducked in again, holding on with one hand. The water felt wonderful against his stump, soft and cool. He wanted to jump in, but he couldn’t swim and the current was too fast. But he opened his eyes under the surface and watched the muddy trail leave him and head downstream.
As he watched, he noticed that the odd stone lumps on the sides of the channel had been prised loose by the water and were now moving. One slowly tumbled towards him, somehow drifting against the current. It had an odd thin line down the middle, he noticed. It came nearer and the line grew thicker, and then the whole stone seemed to open up. Coll stared in astonishment as it bobbed forward, the opening lined with small sharp stones that looked like … well, like…
Teeth.
And suddenly Coll realised the stone wasn’t drifting, it was swimming towards him, fast, and its mouth was glinting with diamond-sharp teeth, and as he jerked his head out of the water the jaws closed in front of him with a SNAP!
“Argh!” he spluttered, pulling back. His one hand slipped against the wet sides and he plunged back into the water, losing his grip. The current seized him and dragged him under. He yelled again, but water muffled his shout and filled his mouth and he choked. All he could hear was the pounding wash, and the world was white and churning, turning him upside down. In a tiny moment of clarity he stared ahead and saw the horrible stone creature, its jaws wide open, and more behind it. It lunged forward, and Coll flung his arm up—
A spear stabbed through the creature, driving it down and pinning it to the bottom. A wispy trail of blood seeped out, and the other boulders turned and made for it in a feeding frenzy. Something grabbed the back of Coll’s shirt and heaved him upright. He stared up.
Namir stood waist-deep in the water like an iron statue, her legs braced and unmoving in the current. Her face was as sharp as a blade, glaring at the rock creatures, and the arm lifting Coll bulged with muscle. Another creature drifted close and she drove her spear down again and stabbed right through its shell.
“Ups-a-daisy!” came a cheerful voice. Now arms lifted Coll and hoisted him from the water, and he realised they were Dolen’s. On the bank, Fillan, Rieka and Brann were staring at him in shock.
“Got him, Mrs B!” called Dolen.
Namir nodded. Carefully she waded back, holding her spear aloft and scanning the water. She heaved herself out of the channel with one arm and stood, gazing down at Coll. Her eyes were flat and careful.
“All right?” she asked.
Coll gaped at her. “Y-yes,” he managed, and she nodded.
She reached down and picked up her shawl, pulling it over her T-shirt. But before she did, Coll saw her arms. They were covered in tattoos, a single pattern of fluid stripes that ran from wrist to shoulder. Each stripe was solid black, three or four centimetres wide, waving and curling round her.
Namir saw him watching but said nothing. She stalked away.
“Well now,” said Dolen cheerily. “That was an adventure, eh?”
The water slowed after a while, as Dolen had said it would. The raging river became a stream, and then a trickle, and soon all that was left were puddles in the bottom of the channel. The creatures settled down like boulders again. Coll stared at them with loathing.
“Rockjaws,” said Dolen. “Nasty little critters, but they stay in the water. Should have warned you – wasn’t expecting you to take a dip!”
Rieka gazed into the cave. “How often does the water come?”
“Every thirty days,” said Dolen. “Like clockwork. Runs for thirty minutes, then stops.” He glanced at Rieka. “You’re thinking something makes it happen, right? Sharp girl like you is already trying to work it out.” Rieka nodded and Dolen smiled. “Often wondered myself. It comes from the north-west, maybe north – it’s curved, I reckon. Beyond that…” He shrugged. “You could go inside and see where it ends up, but I don’t recommend it – not with these fellas around!” He laughed and swept one arm towards the rockjaws.
“North…” murmured Rieka, sharing a glance with Coll.
Dolen stowed his now full water canisters and barrels, then pulled out the stove and made dinner. Behind him, Namir emerged from the back of Beetle and started tinkering with the water filter. She ignored them at first. But after a few minutes she stopped, smiled grimly to herself and sat down next to Coll.
“How are you?” she asked.
Coll had dried himself off, and refastened his arm. He gazed at her. “You’re Tiger,” he said.
Brann stiffened and leaned back. Rieka’s eyes flashed. The woman said nothing. Dolen stirred his soup without speaking. “Those tattoos are Tiger,” continued Coll. “Aren’t they?”
“We’re Beetle,” said Namir. “That’s all.”
“But you were Tiger, weren’t you?” Coll insisted.
