In the third hour of waiting, several other members of the camp were growing restless, some whispering to each other and looking over at Illiun with expressions of concern. Their leader, however, did not stir. Instead he sat and waited patiently, as though utterly certain of the children’s safe return.
In the fourth hour of waiting one of the silver-eyed men knelt down and conferred with Illiun. Silus was close enough that he could hear what the sentinel said.
“Units four and seven have stopped reporting in.”
“‘Stopped reporting in’?” Silus said. “What does that mean? You said that we could trust these things, Illiun.”
For the first time since Silus had met him, Illiun looked unsure of himself.
“Fark this,” Silus said. “We’re going after them. Kelos, Dunsany, Bestion, Katya — you’re with me. Anybody else who wants to help, you’re very welcome, though I suggest that you arm yourselves first.”
Katya looked relieved that they were finally taking action, while Dunsany belted on his sword with a look of satisfaction, almost as though he had felt the embrace of an old friend.
“We’ll find them,” Silus said to Katya. “I know that they’re alive.”
“Really. Is this prescience another one of your powers?”
Silus said nothing, already aware of just how dreadful the consequences would be for him and Katya if they didn’t find their son.
Shalim and Rosalind joined them as they set off, as did Illiun and a handful of others, including one of the sentinels. They called out to the children as they went, although the night seemed to swallow their voices almost as soon as they were out of their mouths. The desert was still and the light of the campfire faded quickly behind them. The going became harder as the slopes of the dunes became more pronounced. They would struggle uphill, ankle-deep in sand, only to reach the crest of the hill and find themselves struggling to keep upright as they half-tumbled down the other side. After mere minutes of this, Silus’s ankles were singing with pain.
“Surely they can’t have gone far?” he said to Katya. “I mean, why would they even have wandered away from camp? What is there to see out here?”
“Perhaps they were taken,” Katya said.
“Don’t say that. Please. We must hope for the best.”
They crested the next rise, to see a scattering of huge stones protruding from the sand: boulders, scoured smooth by the desert winds, their surfaces so polished that even in the dim starlight Silus could see his reflection in them. They looked like great black jewels. He wondered whether this was what the desert itself was made from, these huge rocks whittled down to grains by the passage of time and the weather.
Ahead of them, the sentinel had stopped before a cluster of the dark rocks. He held his metal staff ahead of him, his head cocked to one side, as though listening to something. Then he placed his staff on the ground and began weaving around the rocks. At first he appeared to be randomly careening amongst the boulders, but as Silus watched, he realised the sentinel was walking around the same seven stones, in a wide double loop.
“Unit twelve,” Illiun called. “Have you found something?
But the sentinel didn’t respond; instead he was humming to himself, a disconcerting sound that had something of the angry drone of wasps about it.
Drawing closer to the stones around which the silver-eyed man was dancing, Silus could taste an unpleasant sour metallic tang in the air. He looked down to see the hairs on his arms rising.
“Magic?” he asked Kelos.
“No, I don’t think so,” said the mage. “It feels a bit like that first time we stepped aboard Illiun’s ship; that same charge in the air.”
“Shouldn’t somebody offer to be our silver-eyed pal’s dance partner?” Dunsany said. “It looks like he’s getting a bit twitchy.”
The speed with which the sentinel was circling the stones was increasing, each loop drawing him fractionally closer to the rocks until, inevitably, he came crashing to a halt.
The sentinel lay in the sand unmoving, staring up at the boulder with which he had collided.
“What the hells was all that about, Illiun?” Katya said. “Was the thing supposed to do that?”
“Unit twelve, report.” Illiun called.
The sentinel didn’t move.
“Unit twelve, report!”
Dunsany went to stand over the prone figure. The silver was fading from the sentinel’s eyes, flickering slightly as they dimmed. His mouth was stretched into a rictus grin and his fingertips danced lightly over the sand. Dunsany knelt down and put his fingers to the sentinel’s throat but could feel no pulse. He leaned over and put his ear close to the silver-eyed man’s mouth, listening for any sign of breath. But instead of the soft whisper of exhalation, there was a low buzzing sound, slowly gaining in pitch.
“I think…” Dunsany called, “I think that he may be okay; though it’s sort of hard to tell.”
The sentinel screamed: a sound like a thousand stuck pigs squealing in a vast abattoir; a sound so terrible that it was a small mercy that Dunsany was instantly deafened in his right ear. It was no consolation for the pain he felt, however, as the sentinel jerked upright, gripped his face and attempted to pull the flesh from his skull. Dunsany thrashed around with his right hand, trying to get a grip on his sword, but his fingers kept skittering across the pommel.
In the end it took not only Illiun, but also Silus, Katya and Kelos, to pull the sentinel away from Dunsany, by which time blood was trickling out of his ear and angry purple bruises were rising around his face. Kelos skewered the twitching sentinel on his blade.
Even with a sword sunk halfway to the hilt in the sentinel’s chest, he still took a long time to die. Instead of blood, a pale blue viscous fluid slowly leaked from his wounds. From his mouth came a pungent smell, like burning hair.
“I thought that you said we could trust the sentinels?” Dunsany said, rounding on Illiun and gripping him by the front of his shirt. “That thing almost killed me.”
“I don’t understand,” Shalim said. “The sentinels have never done such a thing before. Illiun, what happened?”
“We felt a charge in the air, just before the sentinel went crazy,” Kelos said, turning to Silus for confirmation.
“Yes. Something like the feeling you get before a thunderstorm.”
Illiun walked up to one of the stones and put his hand to its surface. When he pulled it away, Silus noticed small flickers of static electricity leaping from the stone to his palm. “It’s in the stones,” he said. “Whatever affected the sentinel is in the stones.”
“Then we better find the other two before they harm our children,” Rosalind said.
They followed Rosalind and Shalim past the corpse of the sentinel and further out into the desert.
It wasn’t long before they heard Zac and Hannah crying.
“Oh, thank the gods,” Katya said, running towards the sound.
They came to a depression ringed by more of the black stones, arranged so as to form a natural amphitheatre, at the centre of which was a bizarre, chilling tableau.
One of the sentinels was crouched over Zac with his right knee resting in the middle of the child’s back, pinning him to the ground. Blue froth slowly bubbled from the sentinel’s mouth as he gathered small stones towards himself, dragging them through the sand and carefully arranging them in two neat rows by Zac’s head. Occasionally the sentinel would twitch violently, emitting a noise like sheet metal tearing; eliciting, in turn, even greater cries from the boy.
At first they couldn’t see Hannah, only the form of the second sentinel as he capered around the perimeter of the depression on all fours, throwing up screeds of sand as he suddenly changed direction. But then they all heard the child’s cry and saw Hannah dart between two huge, jagged rocks. She was bleeding from a graze on her forehead and, as they watched in horror, the sentinel raced towards her, lashing out with his metal staff, striking the rock just above her head.