Vale looked thoughtful. ‘If setting traps is his game, he’ll need time to do that and time to double-back and display himself prominently, to tempt us to follow. All this leads to what we were trying to do anyway - reach these Carceri first, and hope we are in time to find him, before Strongrock’s taken for auction.’

Irene was beginning to nod in agreement when it struck her that the sounds of the canal were changing. There was an ambient hush, a silence like a physical thing drifting towards their gondola, swallowing up lesser noises in its wake. She sat upright, pulling out of Vale’s protective arm, to see half a dozen shadowy gondolas moving towards theirs. The approaching boatmen were muffled in black cloaks and moved with inhuman smoothness, their oars barely stirring the surface.

CHAPTER TWENTY-ONE

‘About turn,’ Vale said to the gondolier. ‘You’ll get a bonus, of course—’

‘There’s no bonus big enough to make it worth crossing the Ten,’ the gondolier said, his voice shaking. He brandished the oar at them threateningly. ‘You stay right where you are.’

Pleading innocence was not going to help. The question was: how much disturbance was Irene prepared to make in order to get away safely.

Quite a lot, she decided.

She scrambled to her feet and took a deep breath. ‘Canal water, freeze deep and thick!’ she shouted at the top of her voice.

Her words hung in the silence. Then their gondola came to an abrupt halt, throwing Irene to her knees. Vale grabbed her and pulled her upright again, steadying her. The silence was gone; the air was now full of the creaking of trapped wooden boats, and a bitter chill rose from the suddenly firm surface of the canal. The approaching gondolas were among the trapped boats, and the men in them seemed also briefly frozen in shock.

‘Will the ice hold us?’ Vale asked, getting to the point.

‘It’d better,’ Irene replied as she swung herself over the side of the boat: the ice groaned under her weight, but didn’t break. She hastily began shuffling towards the canal bank - the surface of the water had frozen in peaks and ripples, giving her feet some purchase. Besides nearly drowning, her boarding-school experiences had included dangerous adventures on semi-iced lakes, so it wasn’t the first time she’d done this. She steadied Vale as he nearly slipped. Crashes from the far gondolas suggested that their pursuers were finding it more difficult.

Under normal circumstances, crowds of curious bystanders would have been mobbing the bank, but the presence of the Ten’s own secret police had cleared the area very effectively. Irene and Vale scrambled up off the ice without anyone getting in the way. They’d gained perhaps a minute, but not more. And the black-clad masquers were scrambling across the ice towards them with more confidence now.

Time to slow them down a bit more. ‘Ice, break!’

Interestingly, the ice didn’t all fracture in the same way. Some of it crumbled into tiny fragments, sinking into the water like dust, while other pieces stayed in large chunks, miniature icebergs drifting downstream on the canal. The men on the ice dropped into the freezing water in eerie silence, but they were still struggling towards Irene and Vale.

Vale grabbed Irene’s arm and towed her into the nearest alleyway, cutting across a narrow bridge and between a row of old houses. ‘We need to evade them,’ he said, and she wondered if retreating into the obvious was a habit of his.

‘So where was Kai last seen?’ Irene demanded.

‘The Piazza San Marco,’ Vale answered. He gave her a boost over a stone wall between two houses and into a private garden, then vaulted over himself. ‘The Campanile.’

‘Clearly the Ten believe in the principle of hiding in plain sight,’ Irene muttered. She kicked a free-range chicken out of the way in a squawk of feathers. ‘Excuse me,’ she added to an outraged householder who’d opened his back door to complain. Distraction, distraction - they needed a distraction. ‘Vale, if we were foreign spies, here with sabotage in mind, what would we target?’

‘The Ten themselves,’ Vale suggested, ‘or we’d want to assassinate the Doge, or blow up the Arsenal. But the Arsenal would be easiest, as both it and the Campanile are north-east of here. So can you make our pursuers think that’s our aim?’

‘I can try.’ But how, she wondered. She remembered the Venetian Arsenal now: a complex of shipyards and armouries, so huge and industrial that it had supplied images for Dante’s Inferno. And she had enough grasp of the city’s geography to know that it was directly on the water, looking out across the scattered islands to the open sea.

Running feet echoed in the distance behind them. And even if Vale had a semi-preternatural ability to find his way through a city’s back-alleys on only a day’s acquaintance, the Ten’s servants were still close behind and gaining.

She needed to make a nice obvious trail if this diversion was going to work. ‘We need to get to the waterside,’ she said briefly. ‘I’m going to need a boat, and we’ll need something to put in it.’

Vale tilted his head, then nodded. He changed direction, leading her down a street to the right, towards the larger noises of the sea front.

The two of them burst out onto a small quay, in between two rows of inns and shops, with half a dozen rowing boats tied up at the far end. Perfect. Though it was also a dead-end, with nowhere to go but the water. So this idea had better work.

‘Untie that one,’ Irene directed Vale, pointing at the closest boat. She dragged an oiled canvas cover from the one next to it and shoved it into the first boat, tossing her shawl in on top for good measure. From where they were standing, she could see the great curve of the Venetian lagoon and the open sea beyond. At this distance, the Train lay across the water on its protruding platform like a chain, but beyond it she could see the buildings on the other side of the curve, half a mile or more to their east. Now that she knew where to look, the Arsenal was obvious. Even at this time of night, it blazed with forge-fires, its silhouette irregular with flaring chimneys, high walls and ships’ masts, and smoke rose from it into the cloudless night.