It was a villa farm with a basically Roman look, despite the usual provincial differences of layout, and a much-reduced scope from the vast estates of Italy. We entered by a small grassy path that ran between the barn and a duck pond, passed some apple trees, took a detour by an empty byre, avoided a loose pig, then came to a colonnaded house.

Indoors there was a square, Germanic hall with a central hearth where the milder Mediterranean climate would have allowed an open atrium with a pool. Julia Fortunata had imposed deliberate Roman style: drapery in sophisticated colouring, scroll-ended couches, well-placed statuettes of Greek runners and wrestlers, a side-table with a small library of scrolls in silver canisters. There were touches of drama too: sudden swags of purple cloth and multiple bronze acanthus-leaf lamps.

When she appeared, even though we knew she had been anxious to see me, she gave me her hand calmly and formally. This one would have made a proper wife for a highly placed official, had fortune not made her background good, but not quite good enough. While the young bride Maenia Priscilla possessed money and arrogance, Julia had to settle for culture and breeding. She lacked the social benefits that in Rome were conferred by a family of famous ancestors and decades of accumulated cash. She could have married a customs officer and been queen of some small town for life, but what strong-willed woman wants to be dragged down to dull respectability?

If Gracilis was the age I thought-late thirties-then Julia Fortunata must be older by at least enough to show. Justinus had told me their arrangement was known to be of long standing: it had survived the legate's first marriage, and looked ready to outlast the present one. Julia Fortunata travelled with Gracilis on all his postings. Wherever he arrived in Italy or Europe, it was understood that the lady would turn up, settle herself within visiting range, and provide whatever she customarily provided. The set-up had long ago ceased to be scandalous. It seemed a poor life for her, particularly if, as I had deduced, Florius Gracilis was a pathetic man. But sophisticated women pay that price for a senatorial link.

She was fairly tall, and dressed in subdued greyish-mauve material. No real beauty. An angular face, a neck that showed its maturity, and the ankles she crossed as she seated herself to talk to us were hideously bony. She had style, though. Graceful hands arranged her stole. An elegant carriage. Composure when meeting men. She was that rare goose, an independent matron-determined, self-possessed and chic.

'Madam, I'm Didius Falco and this is Camillus Justinus, senior tribune of the First Adiutrix.' As he moved in her social circle, I was willing the tribune to take the lead, but he held back and stood beside me as an observer. Julia Fortunata glanced between us: Justinus in the crisply pleated white tunic and broad purple stripe, quieter and more serious than most of his rank; me ten years older in fact and a hundred in experience. She elected to deal with me.

'Thank you for returning my visit so promptly.' Her voice was refined and assured. It matched perfectly the strong taste of her muted robes and her jewellery, which was sparse but striking-a bold bracelet of Middle Eastern origin, and two huge beaten-gold discs of earrings. Even her sandals had an interesting design. She was a woman who chose things for herself, and liked a touch of the unusual. 'You are conducting some sort of enquiry?'

I made a gesture of assent but gave no details. 'You called at the fort today? I admit I was surprised.'

'It was urgent. I presume that if you are investigating something that affects my old friend Florius Gracilis, you will welcome any help.'

I attempted to unsettle her. 'Maenia Priscilla thinks he may be with you.'

'Can Maenia Priscilla think?' It flashed out like a bright flood of spilt wine, making us jump. 'I'm afraid he's not here.'

I smiled. I could see what might attract him. You knew exactly where you were in this establishment. 'Have you known him long?'

'Ten years.' A slight dryness in her tone acknowledged that we could regard it as more than a nodding association.

I did try to be specific. 'And what are relations between you?'

'Cordial,' she said, in a firm tone.

I let it go. No point being crude. We all knew the tally. 'Julia Fortunata, I am an envoy from Vespasian. I was sent to Upper Germany on another matter, but any odd circumstances that occur while I am here may be related, so they need investigation. You are correct: I should welcome any information about the whereabouts of Gracilis. You may speak completely frankly.'

For a moment she was silent, candidly considering me. I rode out the scrutiny. She reached a verdict and gestured us to a seat.

She had planned what to say. It came out with little prompting and in a concise form. Gracilis had definitely vanished. His friend Julia was extremely concerned. She had asked to see me because she felt that 'other elements' were either taking the matter too lightly, or knew something and were involved in a cover-up. It was inconceivable that he should go off somewhere without mentioning it to Julia in advance.

'Does he even discuss military matters?'

'Within the proper bounds of course.'

'Of course,' I said. At my side the upright Justinus made an effort to control his disapproval. 'Tell me, did he have any worries?'

'Gracilis is extremely conscientious. He frets over everything.' A fidget, eh? A man who harried his men and aggravated his wife no doubt, though probably his mistress of ten years had learned to ignore the agitation. Perhaps, I thought, Julia Fortunata's role in his life had always been to calm him down and boost his morale.

'What most recently? Can you give me examples?'

'Since we came to Germany? In general terms, the political situation. He feared that Petilius Cerialis may have been posted away to Britain prematurely; that subduing the rebels may still be only half complete. He sensed further trouble brewing.' She discussed politics like a man. I wondered if Gracilis was really so fluent himself, or whether he relied on his mistress to frame his thoughts. Yet now, as she described him evaluating the situation as a local commander should, I had for the first time some sense of this man acting with authority. She certainly did well by him.

'What were his relations at the fort?'

'He was very conscious that the Fourteenth legion possessed most of the experience and were to a great extent carrying their colleagues.' She made a slight gesture of apology to Justinus for disparaging the First; her sensitivity was something we had come to expect. Justinus grinned back ruefully.

'Anything else? Money worries?'

'Nothing abnormal.'

'Problems with his wife?'

'Oh, I think Gracilis can handle that one!' Once again she had permitted herself a faintly bitter and contemptuous note, though it was well controlled. Julia Fortunata knew her position was one of strength.

' Other women?' I suggested lightly. She said nothing, reprovingly. 'So what has he been most preoccupied with? Anything to do with the rebels, for instance?'

'He did discuss with me a theory that the chieftain Civilis would refuse to accept defeat and might try to rally support again.'

'Any evidence?'

'Nothing firm.'

I smiled. 'Had he decided to do something about it?'

'He would like to finish the task Petilius Cerialis left behind. Gracilis is ambitious, naturally. Dealing with Civilis would enhance his status in Rome and win the Emperor's gratitude. As far as I know he had nothing to go on, however.'

To an envoy who also needed enhanced status and imperial thanks, that was reassuring news! 'Does the legate's interest extend to Veleda?'

'He never mentioned her.' It sounded like loyalty. The legate was probably as fascinated by the famous prophetess as any other man.