THE CLAMOURING OF THE WINGS AND THE HAMMERING of the engine was always at its greatest during climbing, so Aubrey sat as mutely as his friends, and prepared himself.

All the other ornithopter crews were under the same orders: to do what they could to stop Dr Tremaine using magical and more direct means. To most of the pilots, that meant engaging in aerial combat. Some were determined to board the skyfleet ships and wreak enough havoc to destroy them. Aubrey was happy for them to attempt all this and more but, having been close to the skyfleet and seen how large each of the ships was, he wondered if they could be brought down by conventional means. Their aborted inspection of the ships suggested that they had many of the qualities of regular vessels, but he was keen to get nearer to see if assuming concrete substance had left the cloudstuff skyfleet vulnerable.

He shook his head. Dr Tremaine’s goal wouldn’t be thwarted by scuttling his fleet. His magic had to be stopped.

But if the other crews could distract Dr Tremaine and keep him occupied, it might give Aubrey and his friends time to find the rogue sorcerer. Then it was up to Aubrey and his magic bullet.

The Armourer at Darnleigh House had enough Symons rifles for Aubrey to take his pick. All of them had been well fired-in and were perfectly maintained, in much better condition than the unfortunate Oberndorf that von Stralick had purloined from that farmhouse. Aubrey had taken a handful of .303 shells and, as Caroline herded the shuddering aircraft skyward, he plucked one of them from his pocket.

It had been the rifle that had let him down at Dr Tremaine’s retreat, bursting like that. He was confident that the principle – and his spellwork – was sound. Now that he had good equipment, all he needed was a decent opportunity and he could trap the master sorcerer. He’d be rendered harmless and could be brought to justice, and the people of Trinovant would be safe.

All Aubrey had to do was to concentrate amid the noise and movement of an ascending ornithopter, then cast a series of fiendishly difficult spells, and make a magic bullet.

THE RUBBERY NATURE OF TIME WAS ALWAYS BROUGHT home to Aubrey when he worked on magic. The intensity of his focus and the intellectual effort needed to shape magic meant that time either slipped past or ground to a halt. This time, when he was done and the Symons had the powerful spell in its breech, he became aware of his surroundings again just as the sound of the wings changed. Instead of all his weight being on his back, pressing him into his seat, he found himself leaning forward. They were levelling off. ‘That’s our ceiling,’ Caroline announced. ‘The Merlin won’t go any higher.’

Aubrey peered out of the window. The earth was far away, Trinovant spread out in all directions from the heart of the city to the faraway outskirts blending into countryside. He could see the other ornithopters labouring upward, all trying to gain altitude.

He tilted his head. Dr Tremaine’s skyfleet was still thousands of feet overhead and maintaining its steady course: a great circle taking it right around the city of Trinovant, from Lambshome in the south to Parmenter in the east, Mayfield in the north and Marbury in the west.

The skyfleet was a daunting sight, clearly visible to all the inhabitants of the city. Having already experienced bombing from dirigibles, Aubrey knew the skyfleet would be bringing dread to the population as Dr Tremaine went about his magical preparation.

The thought gave him pause, and once again he wondered at the complexity of Dr Tremaine’s spellwork. Could the sense of dismay and fear that the skyfleet was imposing be useful in some way? If the consciousnesses he was harvesting were in a state of horror, could this also improve the efficacy of his bid for immortality? This could explain the outrageousness of the skyfleet, the size and the impressiveness of the assault. It was designed to daunt.

‘Time to put the altitude enhancer to work.’ He’d been conscious of the magical field emanated by the box to the rear of the aircraft, a node of magical brightness among many throughout the complex machine. It was quiescent, though, waiting for his spell to activate and control it.

He consulted the tech specs and tried to put aside the effects of casting his magic bullet projectile spell. It was a fourth generation carbon copy, blurry and difficult to read. Someone had scrawled out a series of suggestions but the more Aubrey looked at it, the more it looked like a list of hopeful ideas than a definitive guide to operation. The gist was that an amplification spell needed to be overlaid on the box, one that could be ratcheted up by degrees. Choice of language, duration and – apparently – chance of success was up to him.

Caroline glanced at him – a brief, flashing look that was enough to spur him on. He took out his notebook and pencil and he scrawled out a well-practised standby: a Mycenaean amplification spell he’d used many times before.

‘I’m not sure exactly how this is going to work,’ he said after he pencilled in a reminder to append his signature element, ‘so hold on.’

‘Forewarned is forearmed,’ she said and her hands danced across the control panel. ‘When you’re ready.’

Aubrey gave the spell his best and immediately the Merlin shot upward like a rocket. Feeling somewhat like an earwig caught in a hosepipe at the worst possible moment, Aubrey craned his neck and saw, miles away to the south, Dr Tremaine’s skyfleet.

‘Over there!’ Aubrey cried. ‘The flagship!’

Caroline leaned into the controls. George groaned as the ornithopter tilted, then righted itself, and suddenly they were screaming upward at an angle. Aubrey was pressed against the door and he hoped that the mechanic in charge of door latches had been in top form when putting this one together.

‘We’re close, Aubrey!’ Caroline cried.

The hulls of the skyfleet were growing larger and larger as they neared, flanked by the storm clouds that escorted the fleet like well-built bodyguards helping rich patrons on a night on the town. Around them, other ornithopters were shooting upward erratically, some immediately plunging back down again.

Aubrey hastened to cut off the spell before they rose too far and brought themselves into a direct line with the guns of the fleet.

Instantly, their upward surge halted. The gigantic shape of Tremaine’s flagship cut off the sun and they were plunged into shadow while they bobbed like a balloon a few hundred feet below it.

Satisfied, and unwilling to trust to the altitude enhancer again, Aubrey started the other spell he’d prepared as his part in getting them close to Dr Tremaine’s location without being seen, all of which made his initial plan of bringing magic suppressors to neutralise Dr Tremaine’s magic impossible.

Like most of his outlandish schemes, this one had seemed reasonable when it had first come to him. He’d prepared a spell derived from the Law of Sympathy (‘Like affects like’) to encourage a link between the hull of the warship and the steel of the ornithopter. An attractive link wouldn’t be difficult to propagate, he reasoned, since even though the hull was made of cloudstuff, it was aspiring to steelhood, no doubt aping the form and qualities of steel through an application of the Law of Propinquity. The Law of Attraction provided a backbone to the spell, made all the easier by this propensity of ferrous materials to attract each other.

Awfully exposed, bobbing in the air as they were solely due to the altitude-enhancing device, Aubrey hurried out the spell. They rose, quickly, and before he had time to make any adjustments, they struck the hull with a resounding clang.

They hung there, silently looking at each other, and the whole ornithopter vibrated as if it had decided, on a whim, to become a bell. The cabin shook, the frame vibrated, every single piece of steel or iron around them hummed.

Caroline turned to him, a needless question on her lips. Aubrey wanted to slap himself on the forehead, but decided that fixing the spell would be a better use of his time. He hadn’t anticipated that it would be making every iron-based component of the ornithopter want to embrace the overwhelming iron-like presence just above them. Hurriedly, before the ornithopter could shake itself apart in its eagerness, Aubrey eased back on the attraction spell. Not enough to disengage them, but enough to stop the ornithopter from disassembling itself.

When the quivering all about them diminished and then vanished, Aubrey relaxed the death grip he had on his pencil and notebook. ‘There,’ he said. ‘Just as planned.’

Sophie tapped him on the shoulder. ‘Aubrey, how are we going to get onto the ship?’