‘What now? This is the slaves’ room, citizen. You have no business here.’

‘On the contrary. I have come to tell you we are ready to depart.’ There was a corner of the loaf remaining on the board, and a large knife beside it. There was no one to prevent me and nowhere obvious to sit, so I cut myself a slice and ate it where I stood. Modesta saw what I was doing and found a drinking-cup, filling it for me from the water-jug. I raised it to the horseman in a mock-salute and said, between mouthfuls, ‘We are commanded to leave as soon as possible.’

Ascus made no attempt to hurry. He took another bite. ‘A fine task you have got me landed with. I am now obliged to escort you to Corinium. If Lavinius – or whatever his name is – was not a purple-striper and likely to have important magistrates as friends, I tell you, citizen, I would refuse to go. You don’t need my protection – who would set on you? You haven’t got anything a thief would want to steal.’

I swallowed the remainder of the bread. It was dry, but sustaining, and the water helped. ‘Have they not told you?’ I explained about the raeda-driver. ‘Your task is to make sure he does not escape. You claimed that riding guard was your profession, didn’t you?’

He thumped his cup down on the tabletop and glared at me again. ‘And that’s another thing. Who’s going to pay me for my services? No one has paid me for the slippers yet, though I was specially promised a reward.’

I put my own drinking-vessel down more gingerly. ‘The contract for the wedding-shoes was with Audelia. If we find her, you can hold her to her word. Otherwise I think Publius has agreed to foot the bill. So if you are ready, horseman?’

He flashed the teeth he did have in an unpleasant smile. ‘It seems I have no choice. So, citizen, what are we waiting for?’ He shambled to his feet, and almost before I’d had time to collect my wits he was out of the slaves’ quarters and striding through the yard.

I hurried after him. The gig and its driver were already at the gate, and as we approached I saw the raeda-driver squatting in the carriage on the floor, his hands still bound behind him. He looked up and saw me and gave me a weak smile. ‘Well, citizen, I did not believe that you could get me out of there – except to be bundled to the torturers. I am obliged to you.’

The gig-driver whirled around and flicked his whip across the bloodstained back, making the raeda-driver gasp in agony. ‘Silence, scum! I heard the steward tell you, you are not to speak – and as long as you are in my gig, I’ll see that you obey. If I hear another word from you, I’ll use my whip again.’ He turned to me, all bland politeness now. ‘So, if you are ready, citizen.’

I nodded and clambered up beside him in the gig. The raeda-driver took up so much floor that there was scarcely room for me to squeeze into the seat – a gig is not designed to carry extra passengers – but I contrived somehow. I looked up to find Fiscus grinning in at me, holding out a writing-tablet which was tied and sealed.

‘Don’t drop it, citizen, as you’re going along. That’s my ex-master’s private seal,’ he said, disguising insolence as legitimate concern and exchanging glances with the gig-driver.

A slave had appeared from the stable-block by now, leading a large, recalcitrant black horse. It was a sullen looking animal, shimmying sideways on the rein with wildly rolling eyes, but at least it looked big enough to carry Ascus as was obviously planned. It did not look a comfortable mount, the Roman saddle on its back appeared to worry it. Ascus, however, took one look at the beast and – to my astonishment – vaulted his huge form into the saddle like a child. He leaned forward and rubbed the creature’s glossy head. It quieted at once.

‘If you are comfortable, citizen . . .’ the gig-slave said to me, but he’d already jerked the horses and we were on the move. Comfort is not ever possible in a small, springless carriage along country roads and he was determined to see that there was none. Our speed was such that we constantly jolted up and down so I was obliged to hold on with my one remaining hand – the other was attempting to protect the precious seal. That was difficult enough, but the presence of the prisoner made it infinitely worse. At every bump and pothole he lurched into me and, unable to support himself, his whole weight fell against me and pinned my legs painfully against the seat. Ascus, riding alongside us, saw my predicament and grinned, showing his remaining and discoloured teeth.

No conversation was possible, of course, and – aside from the rattling and jolting of the gig, and my occasional inadvertent grunt of pain – it was a silent drive to town. Never had so short a distance seemed to take so long, and it was with enormous pleasure and relief that I saw the town walls appear.

However, the journey was not over even then. The games had obviously finished long ago, but the gate area was still crammed with carriages and carts of every kind, and citizens in togas were pouring from the town – most of them evidently on their way to dine, if not with Lavinius himself, then at one of the many other Imperial Birthday feasts. There were other, more humble, pedestrians as well, including the travelling stallholders by the look of it – I recognized the palm-seller among them – making for the carts and wagons they had left outside the gates. Some of the crowd were clearly a little worse for wine: the wine-stall was still open just outside the gates, and it was evident that it had done a roaring trade.

I thought it was going to take some time for us to force our way through this jostling and excited crowd and find the raeda, but I had reckoned without Ascus. He urged the horse forward, right into the throng, and people fell back instantly on both sides, lest they be trampled on. The gig-slave simply drove into the space, and in a few minutes we were right up at the gate.

We clattered to a stop. ‘Which is your raeda, scum?’ The gig-slave raised his whip and grinned unpleasantly.

The raeda-driver looked helplessly at me. Answer, and he would be whipped for speaking when he’d been forbidden to; fail to answer and he would still be whipped – this time for refusing to comply. It is the kind of cruel dilemma often used to taunt a slave but it is not often that a servant can employ the trick himself, especially against a freeborn man who would normally be his superior in rank. But the gig-slave had the excuse that he was obeying orders from above, and was enjoying this. I recalled what Cyra had told me earlier about how he had brought the prisoner home at Publius’s request, additionally bound around the legs and feet, ostensibly to prevent the chance of an escape but certainly ensuring a helpless, bruising ride. It occurred to me that the gig-slave would have relished the opportunity.

‘Well?’ he was demanding of his captive now. ‘What do you have to say?’

The raeda-driver raised a weary head and seemed about to speak, but at that moment Ascus cantered back, scattering the people as he’d done before. ‘I’ve found your carriage. I recognized the horses, they were stabled beside my own in Corinium last night. That flabby fellow over there was guarding it just now.’ He made a gesture with his massive hand to where a pudgy slave in temple livery was hastening through the gate. ‘I’ve sent him to his masters, to his great relief. The raeda is all right. The shutters are still up, but I have looked inside and there’s a box.’ He grinned at the raedarius. ‘You are fortunate. On a feast day like today, when the town is full of rogues, it would not have been surprising if it had disappeared. Let’s get the gig over there, and get it loaded on.’

‘When we’ve released the prisoner’s arms,’ I said.

The horseman grinned again. He reached into the lining of his riding-coat and produced a wicked-looking knife.

‘I thought you said you weren’t permitted . . .’ I began.

‘This is for dining purposes, if anybody asks.’ He flashed his gaps at me. ‘But I dare say it will serve for other purposes.’ He leaned into the carriage as he spoke, and sliced the bond in two, as effortlessly as though it were another piece of bread.

The raedarius stiffly moved his arms round to the front and eased his aching shoulders with an attempted shrug. A new bloodstain instantly appeared on his tunic, as though the movement of his back had opened up the wound. I was stiff from jolting, and I ached in every limb and it was difficult for me to climb unaided from the gig, still clutching my precious letter in my hand.

But he managed a wan smile as he joined me on the ground. ‘It is as well the horseman is so big,’ he said to me, in our own tongue again. ‘We could never have moved the box out of the raeda otherwise. That’s it over there.’

He walked so painfully and stiffly that people turned to stare, but he seemed oblivious of the attention paid to him. It was not until we reached the raeda that I understood. He did not stop to look inside at all. He made for the two horses and began to coo to them, whispering and stroking their dark flanks, almost lover-like. ‘Have you had food and drink my lovelies?’ They whinnied up to him.

Ascus was watching all this with a frown. ‘What did he stand accused of?’ he said privately to me.

‘Failing to take care of Audelia and her maid,’ I answered. ‘And failing to account for any kidnappers, or give any other explanation as to where she’d gone.’

Ascus looked thoughtful. ‘She must have been coerced. The last time that I saw her she was happy as could be – thoroughly delighted to be a bride at last.’

‘That is why I wished to look inside the raeda,’ I agreed. ‘To see if there were any signs of force – scratches, or damage, or any sign of blood.’

He nodded. ‘I’ll move that box for you. What’s happened to that gig?’ He gestured to the gig-slave. ‘Get that over here. And be quick about it. We haven’t got all day. This citizen wants to look inside the coach.’

The gig-slave, who’d clearly thought he had a friend, looked mystified at this but brought the carriage up. He leapt down from the driving-seat and gazed inside the coach. ‘That’s an enormous box.’ He put a hand to it. ‘And very heavy too.’

Ascus had dismounted. ‘I’ll put it on the gig.’ He took for granted he could handle it, and doubtless he was right. But I prevented him.

There was something about the nature of the box and its excessive weight that made me say, ‘Before you move it, let’s have a look inside. There might be something of importance there.’

The top had been secured with a heavy lock, but that did not stop Ascus. He used the knife again, this time as a lever, and pushed the lid ajar. But even before he’d fully opened it, the smell had reached me and I knew what we would find.

There was a body in it. A headless body, by the look of it. Ascus did not wait for a command, but reached into the box and pulled it out.

The corpse had been a woman, that was clear at once. Her arms, which had been forced behind her back, proved to finish in mere bloodied stumps where both of the hands had been brutally removed. A woman dressed in a distinctive garb.

Ascus looked at me. ‘Seems as your journey will not be needed now. We seem to have found the missing Vestal after all,’ he said.