The Subura Way emptied at last into the Forum, where the hooves of our horses echoed unnaturally loud about the deserted squares and temples. We skirted the more sacred areas, where horses are not allowed even by night, and headed south across the narrow valley between the Capitoline and Palatine hills. The smell of straw and dung predominated as we passed by the great cattle market of the Forum Boarium, quiet except for the occasional lowing of the beasts in their pens. The enormous bronze ox on its pedestal loomed above us, a great horned silhouette against the starry sky, like a giant minotaur poised on a ledge.

I tapped Eco's leg and he leaned forward, bringing his ear to my lips. 'It's as I thought,' I whispered. 'We make for the Tiber. Are you sleepy?'

He tapped me emphatically twice.

'Good' I laughed. 'Then you keep watch while we drift downriver to Ostia.'

More of Mummius's men waited on the riverbank, ready to take our horses as we dismounted. At the end of the longest pier our boat was ready. If in my sleepiness I had pictured a slow, casual journey down the Tiber to the coast, I was mistaken. The boat was not the tiny skiff I had imagined, but a small barge oared by a dozen slaves with a helmsman at the rear and a canopy amidships, a vessel built for speed and strength. Mummius wasted no time in ushering us aboard. His two bodyguards followed, and we cast off immediately.

'You can sleep if you care to,' he said, indicating the space beneath the canopy, where a mound of blankets had been haphazardly tossed. 'Not very luxurious, and there's no slave woman to keep you warm, but there are no lice. Unless they've crawled off one of this lot.' He gave a sharp kick to the shoulder of one of the rowers. 'Row!' he bellowed. 'And you'd better keep sharper time than you did on the journey upriver, or I'll have the lot of you moved onto the big ship for good.' He laughed without mirth. Back in his element, Mummius was beginning to show a more jovial personality, and I was not sure I liked what I saw. He placed one of his men in charge and crawled under the blankets.