An inch closer and I was planning to spear Jason with my knife. I was only holding off because I knew Thalia was fond of him. Turning Jason into a snakeskin belt was likely to upset her. The thought of what Thalia might do a person who upset her was even more worrying than a squeeze from her pet.

'He looks a bit sick at the moment,' she explained to Helena. 'See how milky his eyes are? He's ready to shed his skin again. Jason's a growing boy – he has to have a new outfit every couple of months. It makes him go broody for over a week. I can't use him in public appearances; he's completely unreliable when you're trying to fix up bookings. Believe me, it's worse than operating an act with a troupe of young girls who have to lie down moaning every month – '

Helena looked ready to reply in kind, but I interrupted the women's talk. 'So how's business, Thalia? The gateman told me you've taken over the management from Fronto?'

'Someone had to take charge. It was either me or a damned man.' Thalia had always taken a brutal view of men. Can't think why, though her bedroom stories were sordid.

The Fronto I referred to had been an importer of exotic arena beasts, and an organiser of even more exotic entertainment for the smart banqueting crowd. He met with a sudden indisposition, in the form of a panther who ate him.

Apparently Thalia, a one-time party-circuit dancer, was now running the business he left behind.

'Still got the panther?' I joked.

'Oh yes!' I knew Thalia saw this as a mark of respect for Fronto, since parts of her ex-employer might still be inside the beast. 'Did you catch out the grieving widow?' she demanded of me abruptly. In fact, Fronto's widow had failed to grieve convincingly – a normal scenario in Rome, where life was cheap and death might not be random if a man offended his wife. It was whilst investigating the possible collusion between the widow and the panther that I had first met Thalia and her collection of snakes.

'Not enough evidence to bring her before the courts, but we stopped her chasing after legacies. She's married to a lawyer now.'

'That's a tough punishment, even for a bitch like her!' Thalia grimaced evilly.

I grinned back. 'Tell me, does your move into management mean I've lost my opportunity to see you do your snake dance?'

'I still do my act. I like to give the crowd a thrill.'

'But you don't perform with Jason because of his off-days?' Helena smiled. They had accepted one another. Helena for one usually gave her friendship reluctantly. Getting to know her could be as tricky as mopping up oil with a sponge. It had taken me six months to make any headway, even though I had wit, good looks and years of experience on my side.

'I use Zeno,' said Thalia, as if this reptile needed no other description. I had already heard that Thalia's act involved an immense snake that even she spoke of with awe.

'Is that another python?' Helena asked curiously.

'And a half!'

'And who does the dancing – him or you? Or is the trick to make the audience think Zeno is taking a greater part than he really does?'

'Just like making love to a man: Smart girl you've picked up here!' Thalia commented drily to me. 'You're right,' she confirmed to Helena. 'I dance; I hope Zeno doesn't. Twenty feet of African constrictor is too heavy to lift, for one thing.'

'Twenty feet!'

'And the rest of it.'

'Goodness! So how dangerous is it?'

'Well:" Thalia tapped her nose confidentially, then she seemed to let us in on a secret. 'Pythons only eat what they can get their jaws around, and even then in captivity they're picky eaters. They're immensely strong, so people think they're sinister. But I've never known one to show the slightest interest in killing a human being.'

I laughed shortly, considering my unease over Jason, and feeling conned. 'So this act of yours is pretty tame, really!'

'Fancy a dance with my big Zeno yourself?' Thalia challenged me caustically. I backed down with a gracious gesture. 'No, you're right, Falco. I've been thinking the act needs pepping up. I might have to get a cobra, to add a bit more danger. Good for catching rats around the menagerie too.'

Helena and I both fell silent, knowing cobra bites to be generally fatal.

The conversation took a turn in a different direction. 'Well, that's my news!' Thalia said. 'So what job are you on now, Falco?'

'Ah. A hard question.'

'With an easy answer,' Helena joined in lightly enough. 'He's not on any job at all.'

That was not quite true. I had been offered a commission only that morning, though Helena was still unaware of it. The business was secret. I mean not just that it would involve working under cover, but that it was secret from Helena because she would strongly disapprove of the client.

'You call yourself an informer, don't you?' Thalia said. I nodded, though with only half my attention on it as I continued to worry about keeping from Helena the truth of what I had just been offered.

'Don't be shy!' Thalia joked. 'You're among friends. You can confess to anything!'

'He's quite a good one,' said Helena, who already seemed to be eyeing me suspiciously. She might not know what I was hiding; but she was beginning to suspect that there was something. I tried to think about the weather.

Thalia tipped her head on one side. 'So what's it about, Falco?'

'Information mostly. Finding evidence for barristers – you know about that – or just listening for gossip, more often than not. Helping election candidates slander their opponents. Helping husbands find reasons to divorce wives they've grown tired of. Helping wives avoid paying blackmail to lovers they've discarded. Helping the lovers shed women they've seen through.'

'Oh, a social service,' Thalia scoffed.

'Definitely. A real boon to the community: Sometimes I trace stolen antiques,' I added, hoping to impose an air of class. It sounded merely as though I hunted down fake Egyptian amulets, or pornographic scrolls.

'Do you look for missing persons too?' Thalia demanded, as if she had suddenly had an idea. I nodded again, rather reluctantly. Mine is a job where I try to prevent people getting ideas, since they tend to be time-consuming and unprofitable for me. I was right to be wary. The dancer exploded gleefully. 'Hah! If I had any money, I'd take you on for a search-and-retrieve myself.'

'If we didn't need to eat,' I replied mildly, 'I'd accept the tempting offer!'

At that moment the baby elephant spotted the tightrope and realised why he was being taken for a walk up the ramp. He began trumpeting wildly, then somehow turned around and tried to charge back down. Trainers scattered. With a mutter of impatience, Thalia rushed out into the arena again. She told Helena to look after her snake. Evidently I could not be trusted with the task.