'That document is confidential, Falco.'

I carried on unrolling the papyrus, raising an eyebrow. 'Dear gods, I hope it is! You won't want this muck being made public:' I dropped the scroll behind my stool, out of his reach. He went pink with annoyance at not being able to see which secrets I had been looking at.

Actually, I had not bothered to read it. Nothing but nonsense ever came through this office. Most of the sly schemes Anacrites was pursuing would sound ludicrous to the average stroller in the Forum. I preferred not to upset myself by finding out.

'Falco, you're making my office untidy!'

'So spill the message and I'll go.'

Anacrites was too professional to squabble. Pulling himself together, he lowered his voice. 'We ought to be on the same side,' he commented, like a drunken old friend reaching the point where he wants to tell you just why he shoved his elderly father over the cliff. 'I don't know what makes us always seem so incompatible!'

I could suggest reasons. He was a sinister shark with devious motives who manipulated everyone. He received a good salary for working as little as possible. I was just a freelance hero doing his best in a hard world, meanly paid for it, and always in arrears. Anacrites stayed in the Palace and dabbled in sophisticated concepts, while I was out saving the empire, getting filthy and beaten up.

I smiled quietly. 'I've no idea.'

He knew I was lying. Then he hit me with the words I dread to hear from bureaucrats: 'Time we made it all up, then! Marcus Didius, old friend, let's go out for a drink:'

He hauled me off to a thermopolium the Palace secretaries use. I had been there before. It was always full of ghastly types who liked to think they ruled the world. When secretariat papyrus beetles go out to socialise they have to burrow among their own kind.

They can't even find a decent hole. This was a shabby stand-up wine bar where the air smelt sour and one glance around the clientele explained it. The few pots of food looked caked with week-old crusts of gravy on their rims; nobody was eating from them. In a chipped dish a dry old gherkin tried to look impressive beneath a pair of copulating flies. A misshapen, bad-tempered male skivvy flung herb twigs into pannikins of hot wine boiled down to the colour of dried blood.

Even halfway through the morning, eight or ten inky blots in dingy tunics were Crammed up against one another, all talking about their terrible jobs and their lost chances for promotion. They swigged drearily as if someone had just told them the Parthians had wiped out five thousand Roman veterans and the price of olive oil had slumped. I felt ill just looking at them.

Anacrites ordered. I knew I was in trouble when he also settled the bill.

'What's this? I expect a Palace employee to dash for the latrine door whenever a reckoning hoves into view!'

'You like your joke, Falco.' What made him think it was a joke?

'Your health,' I said politely, trying not to sound as if actually I wished him a plague of warts and Tiber fever.

'Yours too! So, Falco, here we are:' From a beautiful woman slipping out of her tunic, this could have been a promising remark. From him it stank.

'Here we are,' I growled back, intending to be somewhere else as soon as possible. Then I sniffed at my drink, which smelt like thin vinegar, and waited in silence for him to come to the point. Trying to rush Anacrites only made him dawdle more.

After what seemed like half an hour, though I had only managed to swallow a digit of the awful wine, he struck: 'I've been hearing all about your German adventure.' I smiled to myself as he tried to insinuate an admiring tone into his basic hostility. 'How was it?'

'Fine, if you like gloomy weather, legionary swank, and amazing examples of ineptitude among the higher ranks. Fine, if you like to winter in a forest where the ferocity of the animals is excelled only by the bad mood of the trousered barbarians who are holding spears to your throat.'

'You do love to talk!'

'And I hate wasting time. What's the point of this fake banter, Anacrites?'

He gave me a soothing smile, meant to patronise. 'The Emperor happens to want another extraterritorial expedition – by somebody discreet.'

My response may have sounded cynical. 'You mean he's instructed you to do the job yourself, but you're keen to duck? Is the mission just dangerous, or does it involve an inconvenient journey, a foul climate, a total lack of civilised amenities, and a tyrannical king who likes his Romans laced on a spit over a very hot fire?'

'Oh, the place is civilised.'

That applied to very few corners outside the Empire – the one thing these tended to have in common was a determination to stay outside. It led to an unfriendly reception for our envoys. The more we pretended to arrive with peaceful intentions, the more certain they felt that we had their country earmarked for annexation. 'I don't like the sound of that! Before you bother asking, my answer's no.'

Anacrites was keeping his face expressionless. He sipped his wine. I had seen him quaff fine fifteen-year-old Alban, and I knew he could tell the difference. It amused me to watch his strange, light eyes flicker as he tried not to mind drinking this bitter brew in company he also despised. He asked,

'What makes you so certain the old man instructed me to go myself?'

'Anacrites, when he wants me, he tells me so in person.'

'Maybe he asked my opinion, and I warned him you were unreceptive to work from the Palace nowadays.'

'I've always been unreceptive.' I was reluctant to mention my recent kick in the teeth, though in fact Anacrites had been present when my request for promotion was turned down by Vespasian's son Domitian. I even suspected Anacrites was behind that act of imperial graciousness. He must have noticed my anger.

'I find your feelings perfectly understandable,' the Chief Spy said in what he must have hoped was a winning way, apparently unaware he was risking several broken ribs. 'You had a big investment in getting promoted. It must have been a bad shock being turned down. I suppose this spells the end of your relationship with the Camillus girl?'

'I'll handle my own feelings. And don't speculate about my girl'

'Sorry!' he murmured meekly. I felt my teeth grind. 'Look, Falco, I thought I might be able to do you a favour here. The Emperor put me in charge of this; I can commission whoever I want. After what happened the other day at the Palace, you may welcome an opportunity to get as far away from Rome as possible:'

Sometimes Anacrites sounded as though he had been listening at my doorlatch while I talked life over with Helena. As we lived on the sixth floor, it was unlikely any of his minions had flogged up to eavesdrop, but I took a firmer grip on my winecup while my eyes narrowed.

'There's no need to go on to the defensive, Falco!' He could be too observant for anybody's good. Then he shrugged, raising his hands easily. 'Suit yourself. If I can't identify a suitable envoy I can always go myself.'

'Why, where is it?' I asked, without intending to.

'Nabataea.'

'Arabia Petraia?'

'Does that surprise you?'

'No.'

I had hung around the Forum often enough to consider myself an expert in foreign policy. Most of the gossipmongers on the steps of the Temple of Saturn had never stepped outside Rome, or at least had gone no further than whichever little villa in central Italy their grandfathers came from; unlike them I had seen the edge of the Empire. I knew what went on at the frontier, and when the Emperor looked beyond it I knew what his preoccupations were.

Nabataea lay between our troubled lands in Judaea, which Vespasian and his son Titus had recently pacified, and the imperial province of Egypt. It was the meeting point of several great trade routes across Arabia from the Far East: spices and peppers, gemstones and sea pearls, exotic woods and incense. By policing these caravan routes the Nabataeans kept the country safe for merchants, and charged highly for the service. At Petra, their secretively guarded stronghold, they had established a key centre of trade. Their customs levies were notorious, and since Rome was the most voracious customer for luxury goods, in the end it was Rome who paid. I could see exactly why Vespasian might now be wondering whether the rich and powerful Nabataeans should be encouraged to join the Empire and bring their vital, lucrative trading post under our direct control.