She hauled me back indoors and we started to explore the smaller rooms. As we crossed the lofty atrium we passed one of the senators who had dined in the triclinium, already leaving the party with his wife. He nodded goodbye to Helena, with a grim glance at me as if I was just the sort of low-down plebeian rake he would expect to find with a senator's daughter twined around him at a party like this.

'That's Fabius Nepos,' Helena told me in an undertone, not bothering to untwine her arm just to save an old gent's blood pressure. 'Very influential in the Senate. He's elderly and traditional; not inclined to speculate-'

'Looks like we can assume he's one prospective collaborator who is going home early, unimpressed!'

Encouraged, we pressed on into a smaller hall which was decorated with illusionary perspectives of Corinthian columns, theatrical masks, a peacock to please the popular taste, and an elevated Delphian tripod to add a touch of culture for the rest. An extremely serious man with a beard was talking about philosophy. He looked as if he believed himself. The people who were privileged to hear his visionary dissertation looked as if they all thought they would probably believe him too-only nature had denied them the wherewithal to catch his drift.

I did. I thought it was tosh.

When we peeped back into the triclinium, Aemilia Fausta was sitting morosely by herself, plucking at her cithara. We ducked out before she spotted us, giggling together uncharitably. Later we discovered a long corridor set with stone benches for waiting clients, where Fausta's brother and a group of similar well-barbered aristos were standing round with wine cups, watching some of the younger male waiters playing dice on their knees on the floor. Rufus looked surprised to see us, but made no attempt to reclaim Helena so I waved and we sped on.

She seemed in no mood to go sedately back to him. Her spirit was up now. She pushed ahead of me eagerly, sweeping open double doors and rapidly scanning the occupants as if she hardly noticed the ribaldry from the drinkers or the startling combinations of people who had wrapped themselves together for the purposes of pleasure. It was not, as I remarked at the time, the kind of party you would take your Great-aunt Phoebe to.

'I expect an aunt could cope with it,' Helena disagreed. (Thinking about my own Auntie Phoebe, she was probably-right.) 'But let's pray your mother never finds out you came!'

'I'll say you brought me-' I grinned suddenly. I had noticed a welcome alteration in her appearance. 'You've washed your hair!'

'A lot of times!' Helena admitted. Then she blushed.

In one colonnade the musicians who had come with the Spanish dancers were now strumming and fluting for their own amusement-about six times as well as they had played for the girls.

Not a good night for fountains. By one in a small tetrastyle atrium we saw the other senator from the triclinium, spread-eagled between two slaves while he was gloriously, obliviously sick.

'I don't know his name,' Helena told me. 'He had a lot to drink. He's the commander of the Misenum fleet-' As he sagged between the slaves we watched for a moment, admiring the fleet commander's total abandonment.

After half an hour of fruitless search we both stopped, frowning with disgust.

'Oh, this is hopeless!'

'Don't give up; I'll find him for you-' The part of me that wanted to snort that I would find him for myself backed down happily before the part that was smitten with honest lust. When Helena Justina was bright-eyed with determination she looked adorable…

'Stop it, Falco!'

'What?'

'Stop looking at me,' she growled through her teeth, 'in that way that makes my toes curl!'

'When I look at you, lady, that's how I have to look!'

'I feel as if you were going to back me into a bush-'

'I can think of better places,' I said. And backed her towards an empty couch.

•

The annoying bundle wriggled out from under me just as for once I had her in a satisfactory clinch. I landed on the couch in the graceful position the Fates liked to see me in: flat on my face.

'Of course!' she exclaimed. 'He'll have a room! I should have thought of that!'

'What? Have I missed something?'

'Oh, hurry, Falco! Get up and straighten your wreath!'

Two minutes later she had me back in the atrium, where she crisply extracted from the chamberlain directions to his master's dressing room. Three minutes after that we were standing in a bedroom with a dark-red painted ceiling, just off the seafront side of the house.

In the five seconds since we had stepped inside his borrowed boudoir, I had learned two things. Aufidius Crispus was wearing an ensemble which made his ambitions perfectly clear: his dinner robe was deeply dyed with the juice of a thousand Tyrian sea-shells to the luxuriant crushed purple which emperors reckon suits their complexions best. Also, his luck was better than mine: when we came in he had the prettiest after-dinner dancer pinioned on a bed with her rose behind his ear and half her breast in his mouth, while he was banging away at her Spanish tambourine with breathtaking virility.

I turned Helena Justina against my shoulder to shield her from embarrassment.

Then I waited until he had finished. In my business it always pays to be polite.

The dancer slipped out past us, bearing her rose for re-use elsewhere. Evidently the incident had been rapid and routine.

'Beg your pardon, sir; did I put you off your stroke?'

'Frankly, no!'

Helena Justina sat quickly on a stool, more straight-backed than usual. She could have waited outside, though I was glad that she stayed to see me through this. Crispus glanced at her without much interest, then he settled in an armed chair, shuffled his purple folds back into order, plugged his head back through a laurel wreath, and offered audience to me.

'Sir! I'd thank you for inviting me to your highly select symposium, but I came with Aemilia Fausta, so "invitation" is hardly the word!' He smiled faintly.

He was in his middle fifties, with a tireless, boyish look. He had a swarthy complexion with slightly heavy though good-looking features (a fact he was rather too aware of), plus a great array of regular teeth which looked as though he whitened them with powdered horn; he showed them at every opportunity, to emphasize what superb teeth they were and how many he still owned. Beneath the wreath, which he wore as if he was born with it, I admired the careful way his barber had layered off his hair. (Probably that same afternoon, judging by the fatty whiff of Gallic pomade which hung around the dressing room.)

'What can I do for you, young man? Who are you, first?'

'Marcus Didius Falco.'

He leaned on his chin thoughtfully. 'Are you the Falco who sent home my friend Maenius Celer with some colourful bruising and stomach cramps?'

'Could be. Or maybe your Celer just ate a bad oyster and bumped into a wall… I'm a private informer. I'm one of the dispatch boys who have been trying to deliver a letter to you from Vespasian.'

The atmosphere crackled as he sat more alert in his chair.

'"I don't like you, Falco!" Isn't that what I am supposed to say? Then you answer something like, "That's all right, sir; I don't much care for you!"' I could see at once that this would be nothing like convincing the chief priest Gordianus; Crispus was really expecting to enjoy our interview.

'I suppose you'll throw me out now, sir?'

'Why should I?' He was scanning me with some interest. 'I've heard you are an informer! What qualities does that need?'