'He told me,' Helena said to Thalia, as if I had never spoken, 'he was a tycoon with big olive vineyards in Samnium, and that if I tickled his fancy he would show me the Seven Wonders of the World.'

'Well, we all make mistakes,' Thalia sympathised.

Helena Justina crossed her ankles with a swift kick at the embroidered flounce on her skirt. They were devastating ankles. She could be a devastating girl.

Thalia was giving her a practised scrutiny. From our previous encounters Thalia knew me to be a low-life informer, plugging away at a dismal occupation in return for putrid wages and the public's contempt. Now she took in my unexpectedly superior girlfriend. Helena was posing as a cool, quiet, serious person, though one who could silence a cohort of drunken Praetorians with a few crisp words. She also wore a stunningly expensive gold filigree bracelet that by itself must have told the snake dancer something: even though she had come to the Circus with a dried melon seed like me, my lass was a patrician piece, backed up by solid collateral.

Having assessed the jewellery, Thalia turned back to me. 'Your luck's changed!' It was true. I accepted the compliment with a happy grin.

Helena gracefully rearranged the drape of her silken stole. She knew I didn't deserve her, and that I knew it too.

Thalia gently lifted the python from her neck, then rewound it around a bollard so she could sit down and talk to us. The creature, which had always tried to upset me, immediately unravelled its blunt, spade-shaped head and stared balefully with its slitted eyes. I resisted the urge to pull in my boots. I refused to be alarmed by a legless thug. Besides, sudden movement can be a mistake with a snake.

'Jason's really taken to you!' cackled Thalia.

'Oh, he's called Jason, is he?'

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.