“He had a gun. He started shooting at me, and I had to shoot back.” Praying that Theo would not pursue the line of questioning, Hasson turned to the Window and slid the tip of the cutter through the nearest pane. It went into the glass with scarcely any resistance, causing roseate glowing drops to course down the surface.

“I heard my father shouting something at me a few minutes ago,” Theo said, raising his voice above the background noises in the building. “Where is he flow?”

“We’ll talk about that later, Theo — the main thing to worry about right now is…

“Did Barry shoot him?”

“I… I’m afraid that’s what happened.” Hasson moved the blade of the cutter sideways and sliced through a bar of alloy. “Listen, Theo, I’m cutting us an escape door in a window and we’re going to be out of here in a minute or two. I want you to get yourself ready to fly.”

Theo felt for his arm and gripped it. “He’s dead, isn’t he?”

“I’m sorry — yes.” Unable to look at the boy, Hasson concentrated all his attention on the window and felt a dull puzzlement when he saw that a small circular hole had appeared in one of the panes close to his face. The turmoil of his thoughts — about Al Werry and his son and the need to get away from the burning hotel — was so great that the sudden presence of the hole in the glass was an irrelevancy, or at most a fringe phenomenon of little importance. Was the heat from the cutter distorting the window frame and causing…?

A second hole appeared in the glass, and an incredible thought was born in Hasson’s mind.

He spun round and saw Barry Lutze on his feet on the landing. Lutze still had one hand pressed to his forehead, his face was a fearsome bloody mask, and he was using the gun — the gun Hasson had neglected to kick clear of his body. In the act of turning Hasson, driven by pure instinct, hurled the thermal cutter. It flew in a series of eccentric whirls like a binary sun spinning around an invisible companion, touched Lutze’s side, clattered down on to the floor in a fountain of sparks and disappeared into the open pit of the stairwell. Lutze, who had already been lurching unsteadily, fell to the floor. A single convulsive twitch flailed his four limbs simultaneously, then he was motionless, converted in an instant from a human being into something that could have no connection with life.

Hasson, who had been under the impression that the cutter had practically missed Lutze, ran to the body. The fleeting contact, the casual feather-flick from the sun-blade, had gouged a diagonal, smoking, ruinous furrow through Lutze’s chest. This time, it was obvious, there was no need to deprive him of weaponry. Suppressing his natural reactions, Hasson strode to the stairwell and looked down, searching for the cutter, but was unable to see it. There was nothing but a complex tunnel of descending perspectives, obscured by smoke and patchily lit by shafts of hellish light. Swearing hopelessly, he ran back to Theo, who was still standing by the window looking stunned and frightened.

“We’ve lost the cutter,” Hasson said, trying to keep the panic out of his voice. “Do you know the way out of here?”

Theo shook his head. “There’s a door in the roof somewhere, but I couldn’t find it. Somebody always led me in and out.”

Hasson weighed the odds, balancing one vision of dread against another, and came to a decision. “Come on, son, we’re going down and we’ve got to go fast.”

He took Theo’s hand and dragged him towards the stairs. The boy tried to hang back, but Hasson was too strong for him and in a few seconds they were committed to a perilous plunge into the noisome lower regions of the hotel. Having surrendered himself, Theo did his best to match strides with Hasson, but the task was an impossible one for a blind person and their descent became a sequence of mutual collisions, near-falls and extended ankle- twisting slides. Only the fact that the banisters had been installed on those flights saved them from disastrous spills into the central well.

With each successive landing the heat, fumes and noise grew more intense, and when they finally reached the second floor Hasson was appalled to find that it had begun to disintegrate. Some of the slabs were humped like sand dunes and beginning to glow at the edges. Violent tremors coursed through the structure, accompanied by awesome low-frequency groans which suggested that the floor would fall through at any second.

Hasson pushed Theo towards the aperture in the large window. lie gripped the boy by the shoulders and turned him round to face him, at the same time activating his CG unit. The function light on the control panel at Theo’s waist remained dead. Hasson’s gaze traced a practised line over Theo’s flight equipment, and came to a foundering halt at the dips which should have held the power pack. He felt his face contort with shock.

“Theo!” he shouted, thunderstruck by the magnitude of the discovery. “Your power pack I Where’s your power pack?”

Theo’s hand groped around the empty clips. “Barry took it… Mexico… I forgot.”

“It’s all right — there’s no harm done.” Hasson found his lips dragging themselves into the wan semblance of a smile at the inappropriateness of his words as he disconnected his own power pack and fastened it to Theo’s harness.

“I just forgot,” Theo said. “When I heard about Dad… What are we going to do?”

“We’re getting out of here, as planned,” Hasson told him. “You’re going first and I’ll come after you when I grab another pack.”

Theo’s face turned towards the blazing interior of the hotel, blind but cognisant. “How can you…?”

“Don’t argue,” Hasson ordered, completing the electrical connections and bringing the vital pea-sized dome of radiance into being at Theo’s waist.

“We could try it together,” Theo said. “I’ve heard about people going piggyback.”

“Kids.” Hasson pushed him into the rectangular aperture. “Not grown men like us, Theo. Together we’d be way outside basic modular mass. And anybody’s who’s as keen on flying as you are ought to know all about BMM and field collapse.” “But…”

“Outside! I’ve set you at what ought to be just under height maintenance power for your weight, so when you get out there just let yourself float away and sink. Now …gol” Hasson shoved Theo as hard as he could, sending the boy tumbling into the cool black sanctuary of the night sky. Theo, feeling himself topple, added the impulsion of his own legs, turning his exit into a kind of sprawling dive which carried him well beyond the field interference radius, out above the jewelled geometries of the city. He swam in a soft sea of air.

Hasson watched him curve away out of sight, then became aware that the floor slab under his feet had begun to shudder and stir like something possessed of life. He moved off it towards the stairs, feeling curious rather than immediately threatened, and in that instant the slab exploded into fragments. Some pieces fell to the floor below, others were carried upwards in a roaring gout of fire which made the landing as bright as day and seared the moisture from Hasson’s eyes. He threw himself on to the staircase and ran for the upper floors, expecting at any second to find himself treading empty space. Other ominous rumbles coupled with an increase in the general brightness told him that the structure of the hotel was beginning to succumb to the onslaught on an increasing scale.

He tried to increase his speed, forcing his thighs to reach high with every stride, and his breath began to come in raucous, throat-tearing gasps. When he had been running for what felt like a very long time a new fear began to manifest itself, a fear that he might unwittingly have passed the level on which Lutze’s body lay. Or, or, supposing that Lutze had managed to survive a second apparently mortal wound, even for a short time, and was no longer on the landing? Looking upwards, Hasson saw that he was reaching the point where the metal banister ceased to skirt the edge of the stair and he was able to establish his position. He stiff-armed himself away from the wall on to the next expanse of floor and experienced a moment of profound relief when he picked out the inert form of Lutze lying exactly where he had last seen it.