Kai’s shoulders slumped, showing a hint of sulking adolescent. ‘I’m more bound by physical constraints,’ he mumbled. ‘And I can’t actually force one of those creatures out if it’s already inside my wards. I can only set up a boundary so that it can’t get in or out.’

‘Yes, but how large an area?’ Vale pressed. ‘The whole of London?’

‘Maybe,’ Kai said. ‘If you gave me all night. And I’d have to, ah, it would attract attention.’

‘From whom?’ Irene asked. ‘The Fae?’

‘My relatives,’ Kai said. He looked as if he’d like to shrink into a corner at the thought. He seemed to be displaying the heroic nobility of a teenager doing the right thing, combined with the hangdog despair of anticipating the removal of privileges for the next decade. She wondered how old – or how young – he was in terms of dragon ageing. He was so mature in some ways, and so young in others.

Irene frowned. ‘Well, I can ward an area against chaos by attuning it to the Library. That might force Alberich out of an area if he’s already in it – but I can only cover a relatively small area that way. And there are issues of power . . .’ Yes, that was one way of putting it. Warding Vale’s rooms the previous night had been fairly simple. Trying to block a larger area of reality, as it were, would take much more of her energy. She would also need a very thorough description of the area that she was trying to ward. But there had to be some way that she could use this . . .

The zeppelin rocked, throwing Irene off her feet. Something whirred and chittered like locusts in the air outside. Kai grabbed her round the waist, catching hold of a hanging strap with his free hand. Vale managed to balance himself against the far wall. ‘What’s going on?’ he shouted in Mrs Jenkins’s direction.

‘We’re under attack,’ Mrs Jenkins snapped back. She didn’t look away from the controls. Her right hand was locked into the middle of a brass and pewter orrery, and her left hand was pulling at a range of levers. She tugged at something that looked like an organ stop, and frowned when it wouldn’t respond. ‘Trouble to starboard!’

Irene and the others crowded to the window.

‘I can’t see anything,’ Irene said. The only things in sight were rooftops and smog.

‘There!’ Vale declared, pointing a finger. ‘See that vapour trail?’

‘Something small,’ Kai said, leaning over Irene’s shoulder. ‘But I can’t sense any Fae interference.’

‘You forget the Iron Brotherhood,’ Vale interrupted. ‘They have their agents after us too.’

‘Hang on!’ Mrs Jenkins called from the cockpit. The zeppelin lurched again, dragging sideways in a painful, ungainly movement that shook the cabin like a dice cup. Irene and the two men clung to handholds. Lengths of rope that hadn’t been strapped to the walls swung out and flailed in the air, and an unsecured teacup bounced from wall to wall, leaving a trail of cold tea droplets.

‘There he is!’ Vale exclaimed. A man had flown into view. He was strapped into some sort of mobile helicopter unit that whirred its tarnished blades dangerously close to his head, and was wearing an oil-smeared leather helmet and overalls. In one hand he held a heavy pistol, with a cable running from it to something strapped to his lower back. He bobbed in the air, steadying the pistol with his free hand as he tried to line up a shot.

‘Is there some way we can shoot back?’ Kai asked, reverting to smooth competence.

‘Over here.’ Vale leapt into the cockpit and wrenched at a panel above Mrs Jenkins’s head. She ignored him, concentrating on steering the zeppelin. ‘The weapons are kept here on museum vehicles – ah, here they are.’

He pulled out a brace of pistols, tossing one to Kai and another to Irene, who wasn’t too confident about popping off shots at a flying target. ‘Isn’t there anything larger on board?’ she asked. ‘A flare pistol or something?’

Vale spared his attention from smashing a window to give her a sharp look. ‘Really, Miss Winters! A flare pistol on a zeppelin? I thought you were more sensible than that.’

‘It’s not something I’ve ever studied,’ Irene muttered, and decided to keep any other bright ideas to herself for the moment. Kai and Vale were both shooting out of the window and could certainly do so without her assistance. She staggered forward to the cockpit. ‘How much further to the library, Mrs Jenkins?’

‘Almost at it,’ Mrs Jenkins said bluntly, ‘but it’s not going to be a rat’s ass of use, because we can’t land with that maniac out there firing at us. I don’t know what sort of stories you’ve heard about what zeppelins can and can’t do, miss, but I need to hover while someone throws us a line and makes us secure. And that’s what we call, in aviator parlance, a ‘sitting target’. So I hope your friends are good shots, or I’m going to be making altitude and heading north until we lose him. Can’t risk crashing with the streets this busy.’

Vale shouldered over to grab Irene’s arm. Apparently their shots had all gone wide. ‘Miss Winters, can your abilities be of use here?’

Irene shook her head. ‘I can’t affect him or his gear. They can’t hear me.’

Vale stared at her. ‘Hear you?’

‘The Language only works on the universe if the universe can hear it,’ Irene snapped. She was sure that she’d explained this to him earlier. Perhaps she hadn’t. ‘I can affect this zeppelin, but I don’t see what good that would be—’