Plock, plock. His subconscious must have continued to puzzle away at the sounds, for Nish woke with a jerk. It wasn’t a frog – it was the sound made by a crossbow bolt embedding itself into a human body.

He shot up, heart pounding, and stumbled to the nearest embrasure. It was growing light outside, the sun’s first rays illuminating a layer of mist that blanketed everything below the treetops. Nish looked out and the blood froze in his veins.

There were air-floaters everywhere – no, air-dreadnoughts – gigantic vessels each supported by five airbags, and three or four times the length of Flydd’s air-floater. The sides of each vessel were lined with soldiers and at the prows fluttered the silver pennant of the Council of Scrutators. Nish counted nine air-dreadnoughts, then six more from the other side of the chamber. No, seven – a sixteenth hung high above, on watch. Fiz Gorgo was surrounded.

Nish opened his mouth to roar out a warning, but snapped it closed. They’d already shot the sentries and would do the same to him. Besides, no one in Fiz Gorgo would hear him from here. As he ran for the stairs, eye-searing beams lanced out from cartwheel-sized mirrors on the air-dreadnoughts, converging on the secret chambers of the tower below him.

The floor swelled beneath his feet, grew burning hot and the world exploded in his face. The last thing he saw was a nebulous, shield-like bubble rise through the stone like some phantom created by a master of the Art. A corner of it enveloped him just as his head thudded into the wall.

Nish roused to the odours of burning cloth and smouldering leather. He lifted his head but it hurt. He was lying on what had been the floor of the lookout, but was now a jumble of cracked and broken slabs collapsed onto the domed ceiling of the secret chamber below. An edge of rough stone dug into his ribs. Nish slid off it onto a flat slab, which proved to be uncomfortably warm. He rolled onto a cooler one and looked straight through the wall. A triangle of stone had fallen out leaving a hole he could have put his head through. He moved and the walls appeared to shift before his eyes. No, the top section of the tower was tilted and was surely going to collapse.

The slab under him was growing hotter. Nish rolled off onto the next without checking it first, and pain seared through his back and buttocks. He pulled himself to his feet and picked his way across the rubble, his boot soles smoking. The floor in the centre was burning hot. The blast had made an inferno of Yggur’s secret chambers and the floor could collapse through the dome at any moment. He could feel the stone quivering.

He sprang across to the nearest embrasure, where the floor seemed a little more solid, and began beating at the smoking cuffs of his trousers. A section of cloth the size of a saucer fell out and the skin underneath began to blister. He pressed it against the damp stone, then did the same with his boots until the fumes disappeared.

His calf was really stinging now. Scrambling from slab to slab around the perimeter of the chamber to what looked like a marginally safer position, Nish discovered that seepage had frozen on the inner lip of one embrasure to form grey ice. He broke off a piece and held it to the blistered flesh until the burning eased, though as soon as he took the ice away the pain came back, worse than before.

There was nothing he could do about it. Edging to an embrasure that looked over the yard, Nish peered out, careful to make no sudden movement that would betray him. The sky was full of descending ropes, each bearing a squad of armoured troopers clinging to hand- and foot-loops. Several ropes had already touched down on the outer wall and troopers were running along it, taking charge of the defences and picking off Yggur’s guards as they ran from their barracks.

Another squad, already in the yard, was preparing to storm the front doors. Across the far side of the yard a group of twenty or more soldiers, dressed in the distinctive uniforms of Chief Scrutator Ghorr’s personal guard, were breaking into the shed in which the thapter was stored. How could they have known it was inside?

It was the Council! Fiz Gorgo had been betrayed. Nish slid out of sight as an officer glanced up at the smoking tower. Had he been seen? He couldn’t tell. He heard the thunder of boots as a host of troopers surged through the broken front doors.

They’ll get a shock inside, he thought. Yggur, Flydd and Malien would together be the match of a small army. He looked down again and saw a group of warrior mancers follow the advance guard, staves at the ready, and after them squad after squad of heavily armed men. No, there was little hope; the scrutators were too well prepared.

Smoke began to seep up through cracks in the dome. Tossing away the fragment of ice, Nish snapped off another and pressed it to his burning calf. The stone he was standing on was growing hotter and he couldn’t see any way out. The stair was completely blocked by hot rubble. He couldn’t possibly climb down the wet stone on the outside of the tower. His only means of escape was by jumping out one of the embrasures, though below him the drop was eight floors to the paved yard – certain death. In the other directions, the fall was five floors onto the sloping roofs of Fiz Gorgo, which were tiled with thick slabs of lichen-covered rock. He’d either crash straight through, tearing himself to shreds on the broken slabs, or, more likely, break all his leg bones as he landed.

The yard offered a quick death; the roof, lingering agony. If he stayed here, he’d be either cooked or smoked to death. The stone groaned and the tower lurched, as if a lower layer had become plastic. Falling into the inferno was his other doom. Nish hopped from foot to foot. The soles of his boots were smoking again. There was nowhere to go. Or was there?

The horned roof above him was framed with metal rods that had to be cooler than what he was standing on, and if the tower collapsed, there was a faint chance that the roof might hold together. If the tower stayed up, he might, just possibly, survive up there until the inferno went out. It didn’t seem likely but he had no alternative.

Nish eased a smouldering beam out of the rubble, with much burning of fingers and the soles of his feet, and propped it against the wall. He dragged himself up it, caught hold of an iron rod and pulled himself up onto the roof framing.

It was worse than uncomfortable, for the rods cut into his flesh wherever he perched, but it was safer than where he’d been. Before long a curving crack appeared in the top of the dome. The chamber below had turned the orange-red of molten rock. If the conflagration inside was hot enough to melt stone, his end could not be long in coming.

And why delay it, he thought bitterly, since everyone I care about is going to die. Nish had no illusions about his friends’ fate once they fell into the hands of the scrutators. There were no prisons on Santhenar. Minor miscreants were punished by servitude in the front lines, for men, or the breeding factories for women, or by other forms of slavery appropriate to the needs of the unending war. All other criminals were executed as an example to all, the only variation being in the ironically appropriate manner of their deaths.

Tears pricked his eyes when he thought about Irisis, his dearest friend, being tormented by the scrutators. No – he had to cling to hope, no matter how slender. Surely Yggur and Malien, two of the truly great figures from the Histories, were still at large? Yggur was a mancer of overwhelming power and cunning, a legend who had struggled against Rulke himself, back in the time of the Mirror, and even before that. Yggur was more than twelve hundred years old; had seen everything and survived everything. How could the scrutators beat him?