Mummius ushered us from the barge onto a pier. The bodyguards came with us, but the rowers were left behind, gasping and bent double over their oars in exhaustion. I glanced back for a moment at their broad naked backs heaving and glinting with sweat in the starlight. One of them leaned over the bow and began to vomit. At some point during the journey I had stopped hearing their ragged breathing and the steady grating of the oars; I had forgotten them completely as one forgets the wheels of a grinding machine. Who notices a wheel until it needs oiling, or a slave until he turns sick or hungry or violent? I shivered and pulled the blanket around my shoulders to shut out the chilly sea air.

Mummius led us along the riverfront. Beneath the boardwalk I heard the soft lapping of waves against the wooden posts. To our right were clustered a fleet of small riverboats chained to the docks. To our left ran a low stone wall with crates and baskets piled against it in a wild confusion of shadows. Beyond the wall was the sleeping town of Ostia. Here and there I glimpsed the lit window of an upper storey, and at intervals there were lamps set into the city wall, but other than ourselves not a living person was stirring. The light played strange tricks; I imagined I saw a family of beggars huddled in a comer, then saw a rat come racing from the heap, which before my eyes resolved itself into nothing more than a pile of rags.

I tripped against a loose plank. Eco grabbed my shoulder to steady me, then Mummius almost knocked me down with a slap across the back. 'Didn't you sleep well enough?' he barked in his barracks voice. 'I can manage on two hours a day. In the army you learn to sleep standing up, even marching, if you have to.'