We all murmured sympathetically.

`They are very young,' Justinus soothed him. `They needn't know anything about it until it's all long past.' He too stared at the floor. Aelianus was hugging the cushion, keeping quite still now. Since they started to work with me, I had taught them to be synchronised at least when playing with suspects. `It's curious, isn't it?' Justinus then mused. `Would you ever have seen this coming? When you were a child? Were you happy?'

`Oh we were happy,' Negrinus answered miserably. `We didn't know. I didn't know,' he repeated. We all assumed he meant the current legal matters were unforeseen. `I want my children to be happy,' he maundered. `Is that too much to ask?'

We gravely assured him the hope was reasonable, then Justinus went out for a pee.

Aelianus nodded after him. `Problems with his wife. All going bad. Same as you.'

Negrinus was drinking again. Aelianus leaned forward and gave him a refill, but neither of us took up our cups. A brazier spluttered and the flame sank. I closed it down and let the room grow darker. `Not me,' said Birdy. `Never went bad – it was bad all along, see. I was set up. No chance. Set upon and set up…' He slumped even more. `But I didn't know anything then.'

Was this the same thing he didn't know, something specific? Or was he just tipsily rambling?

Justinus returned. He must have raced to the kitchen latrine and back, desperate to make sure he missed nothing. Aelianus shot him a look, in case he had made our confider lose the thread.

`Who set you up then, Birdy?'

`Somebody!' An adolescent retort. He sounded drunk, but not for the first time I experienced a feeling that this man was armoured unexpectedly. He looked around our group with a challenge, though his attitude was amiable. `Now listen, you naughty fellows – this is my private life!' He collapsed again. `Private life… A man has to have a private life, if he is to have a public life. Have to be married. I had to get married. So I married Saffia.'

`Your best friend's wife?' I queried lightly.

`My best friend!' he exclaimed. `My worst friend too…' We were losing him. Suddenly he revived again. `Tested!' he barked. `Knew what she was like, you see.'

`Were you happy with that?' Was Lutea, I wondered. If Lutea's marriage to Saffia had foundered for some reason, would he have wanted to see his friend pick up his departing wife? Or did Saffia actually fall for Negrinus first, so causing the Lutea marriage to fold? It seemed unlikely. Lutea would not have stayed on good terms with her.

`I was happy!' Negrinus retorted expansively. `She was very happy!'

`But it's over now?' nudged Justinus gently.

Negrinus stopped. Now we really had lost him. `Everything is over,' he explained to us in a hollow voice. `Everything is gone for me. I have nothing, I am nothing -'

`Bear up! I was wondering where you can stay,' I said, sounding as helpful as possible. I had decided I could not bear him filling our house with his unhappiness and his lofty attitude. Not now I knew how much he drank. I would not be put under obligations by a weak willed aristocrat whose name was a Forum byword. It was always possible this man made a habit of dropping hemlock into the householder's dinner. `What about your pal? Wouldn't Lutea give you houseroom for a while?'

'No, I can't go there -' His tone was blank. He gave no reason; he was unaccountable to us. I resented the way we were treated like his slaves sometimes. He was in my winter salon; he was drinking my wine. He was making away with a lot of it too.

Justinus pushed him. `But he is your best friend!'

When Birdy just shrugged, Aelianus asked rather pointedly, `Don't you have any other friends?'

At last he responded. `Oh, I'll find someone,' Birdy agreed offhandedly.

After a moment, Justinus came at him again, wickedly. `Your ex-wife has a nice apartment. Lutea arranged it for her, apparently. You should see if he can find another for you!'

Negrinus gave us a swift, rather bitter smile. He dismissed the suggestion without bothering to comment.

`Have you and Lutea fallen out?' I asked him bluntly.

`Oh no. Lutea loves me!' The reply was ambiguous. It was said with some feeling, but could be either truth or a flash of rueful irony. `Don't worry,' he assured us (trying to make me feel bad). 'I'll move on. I'll find a lodging. I won't be in your way – or anyone's…' His misery, or the drink, overcame him again. `Oh gods – what am I going to do? I have nothing – I don't even know who I am any more!'

`No, no! Stop saying that,' urged Justinus, our young idealist `Don't give in, if you are innocent. Defend yourself!'

Negrinus looked around our group. Like a man falling off a ladder I saw the impact coming. `I need someone to help me. I think you people should take on my defence.'

We were all silent momentarily.

It was Aelianus who spoke first, saving the situation for us all. Having a traditionalist on the staff grated sometimes, but freeing us from nonsense because the nonsense broke rules was a useful business tool. `It is inappropriate for us. We don't do court cases. I'm sorry. We do not have defensive expertise.'

Negrinus laughed. `Oh I know that! But here you are, you see. I have nowhere else to turn. You have to look after me.'

He stood up. Now he was being positive again. He was thirty years old, a senator, a curule aedile. He must have been in the army. He had held other posts in government. We were mere curs in his social entourage – and he was certain that in the end we would beg for scraps.

He went off to bed. When he left us, we argued there for hours. He must have known we would. It grew too late for the Camilli to return to their father's house; they were still arguing together when they dragged themselves off to the room where Helena let them doss on guest beds if they stayed over. I had told them, there was no way we could take on pleading Birdy's defence. They had declaimed some high-flown concepts, such as justice demanded it. I had disparaged Justice and her foolish demands. We all felt trapped. The bastard had nailed us to the wall with our own consciences.

`It's not just that he needs help.' Justinus glared at me. I understood his feelings; he had a wife and was about to be a father. He was sick of being reminded that his wife Claudia was an heiress; he wanted money of his own.

`I know. Silius and Paccius are about to make a great deal out of this. So, if Birdy asks us, why shouldn't we have a share in the proceeds?'

`I'm off to dream of cash boxes,' Aelianus muttered blatantly.

I checked the house. Doused lamps. Fastened shutters. I looked in at my children, one feverishly hot under a tangle of bedcovers, one snoring, with dribble all over her pillow. I straightened limbs and quilts. Fine. I found Helena, in our room, also sleeping, her pose strangely like that of my elder daughter, though in fairness she was not dribbling. I tucked her arm under the bedspread. Lifted up a scroll she had been annotating…

Fancy that. Helena Justina had been re-reading the report I produced for Silius.

Every informer needs a girl in the office who will take messages. Mine ran the accounts, kept me in order – and made commercial decisions. While we haggled, with Negrinus and among ourselves, Helena had been working over our interviews, looking for new lines to investigate. She had already decided we were working this case.

I climbed into bed, having moved an oil lamp from Helena's bedside to my own so I could just about see.

I thought about the way Negrinus had come here, first insisting that I was the only person who could or would help him, then changing his mood to moan wretchedly that his position was hopeless, yet now once again demanding that we take on the charges. If he was a victim, ruthlessly targeted by Paccius and Silius, we in turn had been targeted by him. The lads were right: there could be rich pickings here. But I wondered why I felt so sure I did not trust our beleaguered client.