They left the lantern. Bainisk uncoiled some of the rope and tied the end about Harllo’s waist, fumbling with numbed hands on the knot. ‘Take a few deep breaths first,’he said. ‘And then one more, deep as you can.’

The plunge into the dark left Harllo instantly disoriented. The rope round his waist pulled him down and then into the face of the current. He opened his eyes and felt the thrill of shock from the icy flow. Strange glowing streaks flashed past, possibly from the rock itself, or perhaps they were but ghosts lurking behind his eyes. At first he sought to help Bainisk, flailing with his arms and trying to kick, but after a moment he simply went limp.

Either Bainisk would pull them both through, or he wouldn’t. Either way was fine.

His mind began to drift, and he so wanted to take a breath-he couldn’t hold back much longer. His lungs were burning. The water would be cool, cool enough to quench that fire for ever more. Yes, he could do that.

Cold bit into his right hand- what? And then his head was lifted above the surface. And he was sucking in icy lungfuls of air.

Darkness, the rush and gurgle of water flowing past, seeking to pull him back, back and down. But Bainisk was tugging him along, and it was getting shallower as the tunnel widened. The black, dripping ceiling seemed to be sagging, forming a crooked spine overhead. Harllo stared up at it, wondering how he could see at all.

And then he was being dragged across broken stone.

They halted, lying side by side.

Before too long, the shivering began. Racing into Harllo like demonic posses-sion, a spirit that shook through him with rabid glee. His teeth chattered uncon-trollably.

Bainisk was plucking at him. Through clacking teeth he said, ‘Venaz won’t stop. He’ll see the lantern-he’ll know. We got to keep going, Harllo. It’s the only way to get warm again, the only way to get away.’

Hut it was so hard to climb to his feet. His legs still didn’t work properly. Bainisk had to help him and he leaned heavily on the bigger boy as they staggered skidding upslope along the scree-scattered path.

It seemed to Harllo that they walked for ever, into and out of faint light. Sometimes the slope pitched downward, only to slowly climb yet again. Pain throbbed in Harllo’s legs now, but it was welcome-life was returning, filled with its stubborn fire, and now he wanted to live, now it mattered more than anything else.

‘Look!’ Bainisk gasped. ‘At what we’re walking on-Harllo, look!’

Phosphorescent mould limned the walls, and in the faint glow Harllo could make out the vague shapes of the rubble underfoot. Broken pottery. Small fragments of burned bone.

‘It’s got to lead up,’ Bainisk said. ‘To some cave. The Gadrobi used them to bury their ancestors. A cave overlooking the lake. We’re almost there.’

Instead, they reached a cliff ledge.

And stood, silent.

A vertical section of rock had simply plummeted away, leaving a broad gap. The bottom of the fissure was swallowed in black, from which warm air rose in dry gusts. Opposite them, ten or more paces across, a slash of diffuse light revealed the continuation of the tunnel they had been climbing.

‘We’ll climb down,’ said Bainisk, uncoiling the rope and starting to tie a knot at one end. ‘And then back up. We can do this, you’ll see.’

‘What if the rope’s not long enough? I can’t see the bottom, Bainisk.’

‘We’ll just find more handholds.’ Now he was tying a loop at the other end which he then set round a knoblike projection. ‘I’ll throw a snake back up to dislodge this, so we can take the rope with us for the climb up the other side. Now, you go first.’ He tossed the rest of the rope over the edge. They heard it snap out to its full length. Bainisk grunted. ‘Like I said, we can find handholds.’

Harllo worked his way over the side, gripping hard the wet rope-it wanted to slide through, but if that happened he knew he was dead, so he held tight. His feet scrambled, found shallow ledges running at an angle across the cliff-face. Not much, but they eased the strain. He began working his way down.

He was perhaps three body-lengths down when Bainisk began following. The rope began swaying unpredictably, and Harllo found his feet slipping from their scant purchases again and again, each time resulting in a savage tug on his arms.

‘Bainisk!’ he hissed. ‘Wait! Let me go a little farther down first-you’re throwing me about.’

‘Okay. Go on.’

Harllo found purchase again and resumed the descent.

If Bainisk started up again he no longer felt the sways and tugs. The rope was getting wetter, which meant that he was reaching its end-the water was soaking its way down. And then he reached the sodden knot. Sudden panic as he sought to find projections in the wall for his feet. There were very few-the stone was almost sheer.