Originally the bodyguard must have numbered around five hundred. Some had died, some had drifted elsewhere, yet a hard core stayed on, dreaming of the good old days as fighting men do. Now they were pushing pension age – had they been given pensions. From their shabby dress and faded energy I deduced that public handouts for these one-time palace servants were few. In Roman politics during the mad days of the Julio-Claudians, loyalties had tended either towards Nero or Claudius; political advancement had depended on alliances made with one or the other; and Vespasian was a Claudian supporter. When Nero died and he came to power, fortune finally stopped smiling on these men.

It was thirty years since their heyday. They had not so much run to seed as decayed into compost. I found a mildewed huddle of about fifteen, teasing out a flagon or two at their regular lunch club. A withered Ubian waiter, who must have served their bread and blood-sausage for forty years, tottered away to fetch extra wine that I paid for, muttering what sounded like bitter Ubian curses under his onion-flavoured breath. The old warriors regarded me with greater toleration, aware that few people nowadays would stand them a warm toddy on a cold morning, but even they failed to reach my classification of 'friendly'.

I seemed to remember that in the old days the German bodyguard had been selected for size. Now the big men were stooped in the shoulder but their once-giant frames supported heavy bellies. They looked truculent. I had had a fight with another group of these bullies a few years ago and it had been vicious. These were older now and might not be able to catch anyone who ran away very fast, but if you stumbled as you tried to escape, they could kill you just by rolling on you – and I was pretty sure they would do it. When the drinkers banged down their metal cups with their fat fists, the reverberation shook sheets off the washing lines three streets away. It was deliberate. Nero's bodyguard had always been violent and uncontrollable. Nowadays they were lazy old slobs and their blond plaits had thinned out to sad wisps, but they were still off-putting. They did not like me either. Once again I was hamstrung by my order to keep Veleda's name out of my enquiries. And once again, I thought I saw expressions in the watery blue eyes of some here which said they knew exactly why I had come to question them.

As a lead-in, I asked whether they had had a visit recently from the Praetorian Guard. This elicited a loud burst of laughter and boasting about how they bettered the Praetorians. I joked chummily that the Guards were having a bad week, and we settled down pretending to be allies. It was temporary.

The Praetorians, never famous for subtlety, had come right out and admitted they were looking for someone, a woman from the old guards' home country. I asked if they had had any visits from anyone like that, and they responded rudely that they wouldn't tell me if they had. They must have spurned the Praetorians with the same derision. While this meant that the Praetorians, and Anacrites, had failed to get ahead of me, it also meant that all of us were getting nowhere.

The Germans continued drinking the wine I had paid for, pretty well ignoring me. I considered them. Enough had been said for me to suspect that in general they would show no sympathy to a woman. Veleda's fall into captivity would be an excuse to ignore her. Since they spent their time bemoaning the loss of the old days, they were also antagonistic to the younger generation that Veleda represented. I asked if they had sons; a few did, but they were serving in the legions and I guessed that if those soldiers ever came home, there would be distrust and family arguments.

I wondered which side of the River Rhenus these warriors originally came from. They could even be a mixture of tribes. Although Nero was best known for using this Rhineland protection force, it had been instigated earlier, by Augustus; other emperors and generals had employed them too. Vespasian had stopped that; now the Emperor was meant to be the Father of his Country, utterly loved by his people. Rule by threat had given way to rule by coercion. While bad emperors would continue to be set upon and stabbed, we all pretended the public were devoted. It had become embarrassing to employ foreigners for imperial protection, because that implied that the Father of his Country could not trust his own.

Suddenly one of the bleached braggarts produced a coin from his bosom. As if he sensed that I was mentally condemning his brothers and him as outdated, he flattened it on the boards in front of me. Typical of imperial propaganda, it showed Nero on a box, addressing three figures in military dress, whom I deduced must be members of his German guard. 'We are history, Falco!'

'You must be very proud,' I said, pretending to be overawed. I would have felt uncomfortable surrounded by this number of manicure boys at a public bath house. These overweight monsters made me nervous. I had been aware of men coming and going in the low-roofed hall where we were squashed. They could be taking messages, summoning reinforcements. I could no longer see the Ubian waiter. Perhaps someone had recognised me from that fight I had had with the others from their group five years ago. Perhaps somebody had remembered how on that occasion, I had laid out several men who were selling themselves as hired muscle at the house of a certain Atius Pertinax; they fought viciously, but I had left them dying in the road… It was time to leave.

I thanked them for their co-operation and made good my escape. I walked away from the area purposefully, though not so fast as to let anybody watching know I felt nervous. I thought I had managed it safely. I knew the bastards had loathed me but I thought they had let me go.

Only as I slowed down and started to relax did I sense that I had been followed.

Being tracked was always dangerous. I never underestimated the risk. Whether it was general muggers emerging from unlit alleys, hoping to follow some lump of off-guard after-dinner flab and snatch his purse along with his fine linen banquet napkin, or whether it was thugs trailing me specifically for reasons connected with a case, I treated them all as potential killers. Never ignore the half-seen shadow you try to convince yourself was nothing; you may very well end up with an assassin's knife sliding under your ribs. That cart being driven erratically in a road where carts don't normally deliver may have a driver who is planning to run you down. The faint noise overhead may be a heavy flowerpot falling down accidentally – or a pot someone has pushed over with a view to crushing your head. It may be three men dropping down on you from a balcony. 'Hey, Falco!'

Even before I pinpointed them, I knew I was being hunted by Germans. I had recognised the accent. Not the ex-bodyguards. The voice belonged to a younger man. At the breathy shout from my left, I spun around and checked my right. Long practice.

No one rushed me. Two quick steps had me with my back against a house wall. As I scanned around, I pulled my knife from my boot.

My mind raced. I was in the enclave between the Fourth and Sixth Districts. The High Lanes. Not as elegant and lofty as they sound. Somewhere close to the Porta Saluta, named for the Temple of Salus, or well-being. About to be very unhealthy for me.

I knew nobody in these streets. Had no idea where the nearest vigiles station was. Could not rely on local stallholders. Was unsure of the configuration of local lanes and back doubles, if I had to make a run for it… I identified the Germans. Several, and they looked tough.

People were about. A woman stood outside a shop with two young children; she was gazing at produce – knives? cushions? pastries? – while the little girl tugged her skirts, whining to go home. Businessmen were arguing lazily but long-windedly on a corner. A slave wheeled a handcart laden with cabbages, pretending not to notice when he dropped one and it rolled away. Two dogs stopped sniffing each other and stared at me. Only they had spotted my sudden movement and sensed something interesting was about to occur.