`Children?' put in Fusculus.

`Get away,' joshed Passus, playing a well-worn vigiles routine. `She doesn't look old enough!'

`Child bride.' Fusculus grinned back. It might work with a dim girl, but this one was too hard-bitten. Vibia Merulla decided for herself when she wanted to be flattered. She had probably done her share of encouraging men's banter, but now there was too much at stake. She endured the joking with a face like travertine.

`Leave off, you two,' I intervened. I gazed at Vibia benignly. That did not fool her either, but she did not bother to react. Not until my next question: `As the examining officer in this case, you appreciate that I need to look for a motive for your husband's murder. He was rich; somebody will inherit. Can you tell me the terms of his will?'

`You heartless bastard!' shrieked the widow.

Well, they usually do.

She had been about to leap to her feet (very nice little feet, under the bloodstains and cedar oil). Fusculus and Passus were both ready for that. One either side of her, they leaned kindly on a shoulder each, pinning her down on her stool with lugubrious expressions of completely false sympathy. If she tried to break free forcibly, the bruises would last for weeks.

`Oh, steady on, Falco!'

`Poor lady; it's just his unfortunate manner. Please don't distress yourself -'

`No offence!' I grinned heartlessly.

Vibia wept, or pretended to, into a handkerchief, quite prettily.

Fusculus went down in front of her on one knee, offering to dry the tears, which would be unfortunate if they were fake. `Madam, Marcus Didius Falco is a notorious brute – but he is obliged to ask you these questions. A ghastly crime has been committed, and we all want to catch whoever was responsible, don't we?' Vibia nodded fervently. `It would surprise you how many times people get themselves murdered, and we in the vigiles are then shocked to find out that their own closest relatives killed them. So just let Falco do his job: these are routine enquiries.'

`If it upsets you,' I offered helpfully, `I can soon discover what I need to know from your husband's will.'

`Is there a will?' wondered Fusculus.

`I expect so,' Vibia fluttered, as if the thought had never occurred to her.

`And are you mentioned in it?' asked Passus, with an innocent smile.

`I have no idea!' she proclaimed rather loudly. `I have nothing to do with matters of money; whatever other women do. It is so unfeminine.' None of us commented. The remark seemed specific, and I for one filed it in my professional memory under unfinished business. `I expect,' she declared, as suspects tend to do when blaming someone else, `Diomedes is the main heir.'

Fusculus, Passus, and I looked from one to another with knowing bright eyes.

`Diomedes!' said Passus to me, as if this solved a big question. Maybe he was right at that. `Well, of course.'

`Diomedes,' I responded. `There you are then.'

`Diomedes,' repeated Fusculus. `Fancy us not thinking of him straight away!'

We all stopped smiling.

`Young lady,' I said – although the raw calculation in Vibia Merulla's azure-lidded eyes belonged to an efficient nymph who was as old as the cold dawn on the Sabine Hills. `I don't want to press you unfairly, but if he is in the square for this killing, I suggest you tell us rather speedily where we might find him – and who Diomedes is.'

DIOMEDES IS Chrysippus' son.'

Passus was already consulting a list on his waxed tablets. He whistled a little tuneless phrase through his teeth. `If he lives here, he's not in,' he then told me in a low voice.

`He lives with his mother,' announced Vibia coldly. So she was the second wife. With the first still alive, there must have been a divorce. Another nugget to file. None of us commented. No need. Even Vibia's expression showed she understood the implications.

`This lad is an infant?' asked Fusculus, assuming that any older son would live with the father, in normal guardianship.

`He's certainly a spoilt brat who needs looking after!' Vibia snapped. The first wife's boy had definitely upset her somehow. I saw Passus glance at Fusculus, both of them convinced that Vibia `looked after' Diomedes in some sexual way. She failed to notice the innuendo, luckily. It was too soon to harass her in that way, even if we later came to suspect a dalliance.

`He is an only child?' I kept it formal.

`Yes.' She herself had borne none then. She did not appear to be pregnant. Always a good idea to check; many a violent death has been initiated by an impending birth.

`How old is Diomedes exactly?' I had sensed what the scenario might be.

`I'm not his mother; I cannot say exactly!' She looked up at me and stopped playing about. She shrugged. A gauzy stole slipped from her neat little shoulders. `Early twenties.'

`That's exact enough.' Of an age to become a suspect. `When was the mother divorced by Chrysippus?'

`About three years ago.'

`After you came along?'

Vibia Merulla simply smiled. Oh yes; I had got the picture.

`So Diomedes went off to live with his mama. Did he continue to see his father?'

`Of course.'

`They are Greeks,' Fusculus reminded me. His loathing of the cultured folk from the cradle of philosophy was beginning to grate. `Very close-knit families.'

`It's a Roman ideal too,' I rebuked him. `Does Diomedes come to this house to see Chrysippus, Vibia?'

`Yes.'

`Has he been here today?'

`I have no idea.'

You don't normally see your husband's visitors?'

`I do not involve myself in business.' This claim, too, was becoming repetitious.

`But Diomedes is family.'

`Not mine!'

Too crisp. She felt she was defeating our questioning too well. Time to stop it. Better to continue later, when I would know more and might have edged a step ahead of her. I told Passus to obtain details of where the first wife lived, after which I suggested Vibia Merulla might like time to come to terms with her sudden bereavement in quiet female company.

`Is there anybody we can send for, who would comfort you, my dear?'

`I can manage,' she assured me, with an impressive stab at dignity. `Friends will no doubt rush along when they hear what has happened.' `Oh, I'm sure you are right.'

Widows of wealthy men rarely lack for sympathy. In fact, as we left her to her own devices, Fusculus was arranging to leave a `courtesy' vigilis guard at the house; I heard him surreptitiously give the guard instructions to note the names of people, especially men, who rushed along to console Vibia.

Before I left here, I wanted to interview Euschemon, the scriptorium manager. Meanwhile, I asked Fusculus to send a couple of men immediately to the house of the first wife and her son, to put them under close guard until I could get there. `Prevent them changing their clothes or washing – if they have not already done so. Don't tell them what it is all about. Keep them quarantined. I'll be as quick as I can.

I checked one final time that no useful clues had been extracted from the slaves, then I walked back through the lobby to the library. On the way, I had a close look at the side table where the lunch tray

had been placed. Its two pediment feet were carved from that Phrygian marble that comes in basic white, with dark purple variegations. A couple of the wine-coloured streaks turned out to be surface only – dried bloodstains that I rubbed off with a wet finger. It confirmed that the killer might well have stopped here on his way out, in order to pinch that piece of nettle flan.

Unpleasant though it was, I had a last look at the dead man, memorising the ghastly scene in case I needed to recall some detail later. Passus brought me the address of the first wife; I would have liked to be the first to report what had happened – although I bet she would have heard of her ex-husband's death by now.