'So did you notice any odd noises that night?'

'No, Falco.' He sounded pretty definite. Such certainty worried me.

'Are you telling me the truth?'

'Of course!'

'Yes, of course you are:' Did I believe him, though?

Customers were shouting for attention. Epimandos edged towards the main area of the shop, eager to get away from me.

Suddenly I sprang on him: 'Who found the body? Was it you?'

'No, the owner, going up to get his rent:'

So there was an owner! I was so surprised I let the waiter slip away to face the raillery in the bar.

After a moment I let myself out through the back way: a slatted stable door on rusty pins that led to an alley full of dead fish-pickle jars and olive-oil flagons. There were about fifteen years of empties, lurking below a corresponding smell.

Anyone like me who had been coming here for half a lifetime would have known about this unsecured, unsecurable exit. Any stranger could have guessed its existence too.

I paused for a moment. If I had emerged straight after seeing the body I would have thrown up drastically. Controlling myself while I questioned the waiter had helped put it off.

I turned back, looking closely at the stable door in case the killer had left bloodstains to mark his retreat. I could find none. But inside the kitchen area stood pails of water. A murderer could have washed, at least partially, before he left.

Walking slowly, I went round to the main street. As I passed the caupona heading homewards, a tall figure, plainly not a customer, hovered in the shadows outside the Valerian. I took no notice. There was no need for the usual caution. The sinister individual was neither a robber nor a marauding pimp. I recognised that bulky shape, and I knew what he was doing there. It was my friend Petronius, keeping a suspicious eye on me.

I called a mocking goodnight and kept going.

It failed. Petro's heavy footfall pounded after me. 'Not so fast!'

I had to stop.

Before I could start grumbling at him he got in first in a grim tone, 'Time's running out, Falco!'

'I'm dealing with the problem. What are you doing, wearing out the pavements on my tail?'

'I was looking at the caupona.' He had the tact not to ask what I had been up to there myself. We both glanced back. The usual dismal crowd were leaning on their elbows arguing about nothing, while Epimandos applied a taper to the tiny lamps that were hung above the counters at night. 'I wondered if anyone could have made a forced entry to the lodger's room from out here:'

I could tell from his tone he had decided that was unlikely. Looking up at the frontage of Flora's we could see that while the place was open, access would be impossible. Then once the shutters were drawn for the night there would be a blank face on the street side. Above the bar were two deeply recessed window openings, but it would take a ladder to reach them and then climbing in through such a small opening would be awkward. Censorinus would have heard anyone trying to do it well before they were on to him.

I shook my head. 'I think the killer went up the stairs.'

'And who was he?' demanded Petro.

'Don't nag me. I'm working on it.'

'You need to work fast then! Marponius has summoned me to a conference tomorrow about this stinking case, and I can tell you in advance, the conclusion will be that I have to haul you in.'

'I'll keep out of your way then,' I promised, as he growled and let me go.

Only when I had turned the corner did I remember meaning to ask him about the caupona's owner, the mystery rent-collector whom Epimandos told me had discovered the corpse.

I made it back to Mother's in a sombre mood. I seemed no further forward, though I now had some feeling for events the night the soldier died. How his death connected with Festus was a mystery. Censorinus had been killed by somebody who hated him. That depth of emotion had nothing to do with my brother; Festus had been friends with everyone.

Or had he been? Maybe somebody had a grudge against him that I wasn't aware of? And maybe that was what had brought disaster on a man who had been known as one of my brother's associates?

The ghastly scene in the room still hovered on the edge of my consciousness as I went indoors.

I was already hemmed in by problems, and when I entered the apartment I discovered another: Helena Justina was waiting for me, alone.

Mother was out-probably gone to see one of my sisters. She might stay the night. I had an idea things had been arranged that way. Our driver from Germany had already taken his pay, such as it was, and left us. Helena had lent her maid to her mother. Nobody on the Aventine has a maid.

So we were alone in the apartment. It was the first time we had been on our own like this for several weeks. The atmosphere was unconducive to romance.

Helena seemed very quiet. I hated that. It took a fair amount to upset her, but I frequently managed it. When she did feel hurt I lost her, and she was hurt now. I could tell what was coming. She had been thinking all day about what Allia had told her. Now she was ready to ask me about Marina.

Things began quietly. Helena let me kiss her cheek. I washed my hands. I pulled off my boots. There was dinner, which we set about in virtual silence. I left most of mine.

We knew each other too well for preliminary skirmishes. 'Want to talk about it?'

'Yes.' Always direct, this one.

After what I had witnessed that evening, it was the wrong time for an argument, but if I tried to dodge, even temporarily, I was afraid that it could be the end of everything.

I gazed at her while I tried to clear my head.

She was wearing a long-sleeved dark blue dress, winter-weight wool, with agate jewellery. Both suited her; both went back to before I met her. I remembered them from when I first knew her in Britain; then she had been a haughtily independent young woman, recently divorced. Though her confidence had been eroded by the failed marriage, defiance and anger were what I most recalled from those days. We had clashed head-on, yet by some divine metamorphosis that had turned into laughing together, followed inevitably by love.

The blue dress and agates were significant. She may not have thought about it. Helena despised premeditated drama. But I recognised in her appearance a statement that she could be her own woman again any time she chose.

'Helena, it's best not to quarrel at night.' It was honest advice, but came out more like insolence. 'You're proud and I'm tough; it's a bad combination.'

During the day she must have withdrawn into her private self. Helena had given up a great deal to live with me, and tonight she must be as near as she would ever be to throwing that back in my face.

'I can't sleep beside you if I hate you.'

'Do you?'

'I don't know yet.'

I reached to touch her cheek; she leaned away. I snatched back my hand. 'I've never cheated you, sweetheart!'

'Good.'

'Give me a chance. You don't want to see me grovelling.'

'No. But if what I've heard is only half right, I'll be seeing you squirm soon!'

Helena's chin came up. Her brown eyes were bright. Maybe we both felt a thread of excitement, sparring like this. But Helena and I never wasted time inventing pretexts. Any accusations that were about to be flung would carry as much weight as wet sandbags.

I leaned back a little. I felt breathless. 'So what's the procedure? Are the questions to be specific, or shall I just warble cheerily?'

'You seem to be expecting a crisis, Falco.' That 'Falco' was bad.

'I do keep an eye on what you're finding out about me.'

'Have you something to say about it?'