The darkness was a choking blanket, the hiding place of a killer.

Karan fought the shakes and the terror; she had to think things through, calmly and logically. She stirred the fire until it cast dancing shadows through the room, then held her cold feet and hands out to the blaze. It did not warm them.

How could she protect Sulien when she did not know who the Merdrun were, how they would attack, or where, or when? Could the magiz attack from the void, or would she have to come to Santhenar first? And how could Karan, whose gift for the Secret Art had been blocked as a child before it could fully develop, protect Sulien against an alien sorcerer?

Her right thigh throbbed, then the left. After being hurled against the metal side of Rulke’s construct ten years ago, on the desperate day that had changed the Three Worlds for ever, Karan had broken so many bones that no one had thought she would ever walk again. Had it not been for the healing hands of Idlis the Whelm, once her enemy, she would be confined to a wheeled chair – or dead.

The pain kept intruding. She rose and paced, wincing with every step. The signs were clear now – it would get worse until it was unendurable; she would soon have to resort to hrux. But not yet; through force of will she suppressed the pain. She had to be stronger than she had ever been.

She had taught herself to put up with it a little longer each time. To do otherwise, to give in too easily, was to risk hrux claiming her. And hrux addiction was worse than any physical pain.

She took a small key from a drawer, grabbed a lamp and went out. Her hands were shaking so badly that she kept dropping the flint striker; it took twenty clicks to light the wick. In the larder she climbed the stepladder and, standing on tiptoe, reached for the little metal box at the back of the top shelf, out of sight. Karan unlocked it, the key rattling around the keyhole, then opened the lid – and threw her head backwards. Yuk!

The lump of hrux oozed yellow-green muck and the stench, like rotten prawn heads mixed with sour milk, was nauseating. She hesitated; there was barely enough left for two doses and she had no way of getting more. Panic stirred but she fought it down. Dare she try a half-dose? She cut off a pea-sized lump and impaled it on the point of her knife. The longing was desperate now, but not yet… not yet…

The pain howled, it shrieked, it battered at her like a mad thing. She could not bear it another second… and another… and anoth —

No! Hrux aided seeings and she was going to need it; she must not waste it on relieving pain. Karan rubbed the lump across her lips, licked them, shuddering at the stench, lied to herself that the pain would fade and dropped the hrux into her cloak pocket.

She returned to her thinking room and sat in the dimness. Pain sneaked up her thigh, though it was dull pain now; the placebo was working. She needed answers. Why did the Merdrun seem so familiar? What was the summon stone and why did it have to be woken right away, at such cost? How long was it until syzygy, the night of the triple moons – months, weeks or only days? And how, how was she to save her daughter?

There might be a way to answer the first question. Dare she peer through the ghostly webs and treacherous mazes of the void, using the nightmare to try to find Gergrig? Perhaps, under the influence of hrux, she could. It would be dangerous, though not as dangerous as doing nothing. But what if she unwittingly revealed where Sulien lived? The thought was paralysing; how could she take such a risk?

She could not sit here like a helpless victim, waiting for the bruise-eyed magiz to strike Sulien dead. Ah, to drink a life! Karan had to act.

She focused on the end of Sulien’s nightmare, when Gergrig had been speaking to the magiz in the light of Cinnabar’s jade-green moon, and slipped the lump of hrux into her mouth. It was covered in fluff from her pocket. She gagged, choked, swallowed. Her head swirled and tingles ran up and down her legs. She shut the door; she might shout or scream and that would wake the household.

Karan closed her eyes and saw fog, though it cleared suddenly to a true seeing of a place she had seen ten years ago and never wanted to see again – the limitless void between the worlds. It swarmed with savage creatures; she could sense them all around, and perhaps they could sense her too, even in her bodiless state.

She had to be careful, and she had to be quick. Existence in the void was desperate, brutal and fleeting. Even the fittest creatures survived only by remaking themselves constantly, and every being there was consumed by a single urge – to escape.

There were blurred shapes everywhere – some creeping, some scuttling, some waiting with the patience of twelve-legged spiders in steel webs. Karan’s seeing shot past them, zoomed in through shadow into fierce light, focused, then she let out a yelp. All she could see was a pair of deep-set blazing eyes and a jagged black tattoo – a glyph she did not recognise – centred on a man’s forehead.

She retreated until his whole face was in view. It was the first time she had seen Gergrig clearly. A completely bald, domed skull, a heavy beard cropped to a black shadow over an angular jaw, full lips set in a cruel curve, a thin nose and, ugh, a hook-shaped spray of blood on his right cheek. It had clotted in his beard.

Karan shrank back in her chair. Could he see her? What would he do if he did? But his eyes did not move; he was looking down at an object dangling from his neck, a red cube on a fine steel chain. He touched the cube and a faint drumming sounded in her head.

A burst of light from the cube illuminated his eyes, which were an alarming colour, indigo blue with flecks of carmine. Shivers ran across Karan’s shoulders, for the eyes alone were enough to tell her what Gergrig, and presumably the other Merdrun, were.

They were Charon. And that was impossible.

Gergrig rose abruptly. He had to be a foot and a half taller than her, and hard and lean. He reached out as if testing an invisible barrier and momentarily the scene went out of focus, then he dropped his hand and looked over his shoulder.

His troops were gathered behind him. They were heavily armed, bandaged and battered and bruised, and many were red-handed as if they had come straight from the battlefield. All looked jubilant, and all had the jagged glyph on their foreheads. There were many thousands of them, a mighty force armed for war.

An army that could not possibly exist.

Karan cut off the seeing and scrambled to her feet, her heart thundering. How could this be? There were no Charon any more. After Rulke’s death, Yalkara and the few dozen survivors, all age-old, had been the last of their kind. She had said they were returning to the void to face their extinction with dignity.

Had that been a lie?