The bowman fired again, but missed, since the figure had retraced its steps, skipping from the tower roof back down to the battlements, along which other guardsmen were already running, then leapt back over the wall and half-slid, half-fell down it to the ground.

On the other side of the open space in front of the palazzo, the Barbarigo guards were pushing their attackers back into the alleyways beyond, down which they were beginning to pursue them. Ezio took this opportunity to catch up with the figure, which was beginning to limp away to safety in the opposite direction.

When he caught up, he was struck by the person’s light, boy-like, but athletic shape. As he was about to offer his assistance, the person turned towards him and he recognized the face of the girl who’d tried to cut his purse in the market earlier.

He found himself surprised, confused, and – curiously – smitten.

‘Give me your arm,’ said the girl, urgently.

‘Don’t you remember me?’

‘Should I?’

‘I’m the one you tried to rob in the market today.’

‘I’m sorry but this is no time for comfortable reminiscences. If we don’t get out of sight fast we’ll be dead meat.’

As if to illustrate her point, an arrow whizzed past between them. Ezio put her arm round his shoulders, and his round her waist, supporting her as he had once supported Lorenzo. ‘Where to?’

‘The canal.’

‘Of course,’ he said sarcastically. ‘There’s only one in Venice, isn’t there?’

‘You’re damned cocky for a newcomer. This way – I’ll show you – but be quick! Look – they’re after us already.’ And it was true that a small detachment of men had started across the cobblestones towards them.

One hand gripping her wounded thigh, and tense with pain, she guided Ezio down an alley, which led to another, and another, and another, until Ezio had lost all sense of the compass points. Behind them, the voices of the men pursuing them gradually receded and then were lost.

‘Hirelings brought in from the mainland,’ said the girl in tones of great contempt. ‘Don’t stand a chance in this city against us locals. Get lost too easily. Come on!’

They had arrived at a jetty on the Canale della Misericordia. A nondescript boat was tied up there with two men in it. On seeing Ezio and the girl, one immediately started to unloop the mooring-rope, while the other helped them in.

‘Who’s he?’ the second man asked the girl.

‘No idea, but he was in the right place at the right time and apparently he’s no friend of Emilio’s.’

But she was close to fainting now.

‘Wounded in the thigh,’ said Ezio.

‘I can’t take that out now,’ said the man, looking at the bolt where it had lodged. ‘I haven’t got any balsam or bandages here. We must get her back fast, and before those sewer-rats of Emilio’s catch up with us.’ He looked at Ezio. ‘Who are you anyway?’

‘My name is Auditore, Ezio. From Florence.’

‘Hmmn. Mine’s Ugo. She’s Rosa, and the guy up there with the paddle is Paganino. We don’t like strangers much.’

‘Who are you?’ Ezio replied, ignoring the last remark.

‘Professional liberators of other people’s property,’ said Ugo.

‘Thieves,’ explained Paganino with a laugh.

‘You take the poetry out of everything,’ said Ugo, sadly. The he suddenly became alert. ‘Watch out!’ he yelled as one arrow, then another, thudded into the hull of the boat from somewhere above. Looking up, they could see two Barbarigo bowmen on a nearby rooftop, fitting fresh arrows to their longbows. Ugo scrabbled in the well of the boat and came up with a businesslike, stubby crossbow, which he quickly loaded, aimed and fired, while at the same time Ezio flung two throwing-knives in quick succession at the other archer. Both bowmen plunged screaming into the canal below.

‘That bastard’s got goons everywhere,’ said Ugo to Paganino in a conversational tone.

They were both short, broad-shouldered, tough-looking men in their twenties. They handled the boat skilfully and evidently knew the canal system like the backs of their hands, for more than once Ezio was convinced they had turned into the aquatic version of a blind alley only to find that it ended not in a brick wall but a low arch under which the boat could just pass, if they all bent low.

‘What were you doing attacking the Palazzo Seta?’ Ezio asked.

‘What’s it to you?’ answered Ugo.

‘Emilio Barbarigo is no friend of mine. Perhaps we can help each other.’

‘What makes you think we need your help?’ retorted Ugo.

‘Come on, Ugo,’ said Rosa. ‘Look what he’s just done. And you’re also overlooking the fact that he saved my life. I’m the best climber of the lot of us. Without me, we’ll never get inside that viper’s nest.’ She turned her face to Ezio. ‘Emilio is trying to get a monopoly on trade within the city. He’s a powerful man, and he has several councillors in his pocket. It’s getting to the stage when any businessman who defies him and tries to maintain his independence is simply silenced.’

‘But you aren’t merchants – you’re thieves.’

‘Professional thieves,’ she corrected him. ‘Individual businesses, individual shops, individual people – they all make for easier pickings than any corporate monopoly. Anyway, they have insurance, and the insurance companies pay up after fleecing their customers of giant premiums. So everyone’s happy. Emilio would turn Venice into a desert for the likes of us.’

‘Not to mention that he’s a piece of shit who wants to take over not just local business, but the city itself,’ put in Ugo. ‘But Antonio will explain.’

‘Antonio? Who’s he?’

‘You’ll find out soon enough, Mr Florentine.’

At last they reached another jetty and tied up, moving quickly, since Rosa’s wound needed to be cleaned and treated if she were not to die. Leaving Paganino with the boat, Ugo and Ezio between them half-dragged, half-carried Rosa, who had by now all but lost consciousness from loss of blood, the short distance down yet another twisting lane of dark-red brick and wood to a small square, a well and a tree at its centre, and surrounded by dirty-looking buildings from which the stucco had long since peeled.

They made their way to the dirty-crimson door of one of the buildings and Ugo rapped a complex pattern of knocks on it. A peephole opened and shut, and the door was swiftly opened and as swiftly closed. Whatever else had been neglected, Ezio noticed, hinges and locks and bolts were well oiled and free of rust.