And yet … the Council had known where Yggur’s secret defences lay, and had destroyed them from afar without being detected. What if Yggur had been targeted the same way, as he slept? If he was dead, all hope was lost.

The tower gave another of those plastic shudders that made his stomach lurch. Nish clutched the rod with both hands. Waves of colour like inverted rainbows shimmered in the air and, suddenly, he saw right through the stone dome, as he had that ghastly night last summer after his father, Jal-Nish, had forced Nish’s hands into those uncanny quicksilver tears distilled from the destroyed node at Snizort.

He was looking into a seething hell – a cauldron of molten stone seemingly suspended in mid-air where the floor of the lower chamber had once been. What could be holding it up? The roiling globe drifted toward the side wall, only to be repelled back towards the centre. It rotated one way and then the other, emitting little bursts of glowing plasma that licked the soot-coated walls clean wherever they touched.

Nish could only imagine that the ferocity of the blast had been contained by some unknown aspect of Yggur’s secret defences. He prayed that it stayed contained, for the radiating fury looked potent enough to consume the walls of the tower.

The fiery globe swelled, contracted, swelled again and burst open, sending an incandescent jet straight up. Burning through the top of the stone dome, it sucked back then blew an orange spurt of molten rock-glass up through the hole. It arched high across the room, solidifying into a glass lance that split down its length as it cooled, forming a pair of curving blades as sharp as a giant’s scimitars.

The strange-sight that had allowed Nish to see the globe vanished so suddenly that he cried out. An attack of vertigo had him clinging desperately to the rods, his sweating hands slipping on the warm metal.

There came another molten squirt, splitting to form another pair of glass scimitars, and then another and another until the chamber was webbed with them. Nish hung suspended above a hundred razor-sharp blades. It had to be a residue of Yggur’s Art – such perfect, deadly blades could not have formed by accident – but it had trapped him as effectively as any weapon of the enemy’s. If he tried to get down, he’d be sliced like a slab of buffalo on a butcher’s block.

Heat billowed up through the hole, streaming directly over him. His eyelids began to rasp when he blinked. After ten or fifteen minutes Nish could feel his skin drying and cracking in the heat. He was desperate for something to drink.

From his refuge he could see part of the yard. A bound and gagged prisoner was led out to its centre, surrounded by soldiers. The prisoner was an elderly woman, one of Yggur’s kitchen servants. Other servants followed, each with an escort of the scrutators’ finest, then several of Yggur’s guard. After them came Malien, heavily bound, Gilhaelith and, to Nish’s despair, a stumbling, bloody Yggur.

Each new prisoner was a further blow to his hopes. Nish counted them down, and when Flydd and Irisis were dragged into the yard, he gave a groan of despair. The scrutators had them all, from the least to the greatest. He was the only one still free. Ghorr had out-thought them. All the time that Yggur and Flydd had been planning their secret assault on Nennifer, Ghorr had been readying his own vastly superior forces. By the time Tiaan and Malien had reached Fiz Gorgo in the thapter, five days ago, Ghorr’s fleet of dreadnoughts had already been on its way. The irony was bitter.

Down in the courtyard the prisoners were still, all but one. Irisis was struggling, ignoring the cuffs and kicks of the guards. She would do so to the end. Irisis was a rebel and could never be anything else, and Nish loved her for it. The realisation shocked him. He did love her and that made it so much worse.

Nish had expected the search of Fiz Gorgo to take some time, but shortly the scrutators emerged, along with the remainder of the soldiers, and were lifted up to the air-dreadnoughts in suspended baskets. The prisoners and their guards remained in the yard, shivering and stamping their feet.

The inferno below him had begun to cool, but the broken beams on the floor were smouldering, coating him with soot and catching at his lungs. Nish shifted on the rods, trying to find a way down without cutting himself to shreds. He could see none. He might have broken one or two glass blades with his boots, but the ones below were out of reach and dropping onto them was out of the question.

He climbed up under the roof, trying to see if any of the rods could be unfastened. They were fixed solidly, but while he was there Nish happened to glance up through a cracked roof slab and saw that the scrutators’ mechanicians were building a vast ropework construction, like a horizontal spiderweb, above Fiz Gorgo.

They had begun by anchoring the air-dreadnoughts to the outer walls with vertical cables as thick as a big man’s biceps. Now, working a good fifty spans above the ground, suspended ropers were hauling across horizontal ropes, stretching them drum-taut and lashing them into a network.

The instant the great rolls of canvas were lowered, Nish understood what they were doing. They were building a suspended amphitheatre, and it could only be to try the prisoners here. Ghorr wasn’t going to give such a collection of great mancers the least opportunity for escape, but he’d not miss the chance to consolidate his power either. The Council of Scrutators loved its spectacles, and the tale of such a trial would spread like wildfire throughout the known world, to bolster its dread reputation.

Nish tried to calculate how long the construction was going to take. Though the ropers worked with such dexterity that they must have practised the operation many times, it would take hours more to adapt their general design to the specific configuration of Fiz Gorgo. He didn’t know what time it was, for a thick overcast had rolled in from the west and not a glimmer of sun came through it. Nish thought it must have been around ten in the morning. The scrutators would want to complete their grisly business well before dark, which was around five at this time of year, so he didn’t have long at all.

Didn’t have long for what? He was trapped in a half-molten tower likely to collapse at any moment, being cured like a ham in a smokehouse, and his arms could barely hold him up. Half dead from dehydration, he had been reduced to licking the sooty condensation off the underside of the roof slabs. He was unarmed, opposed by hundreds of the toughest fighters in the world and dozens of mancers aching to impress their masters. Furthermore, the scrutators, collectively, represented the most powerful force ever assembled on Santhenar. The very idea of trying to rescue his friends was absurd.

But it would not go away.