‘Oh? Are they on friendly terms? I suppose while she was married to Valerius Aviola she was part of the same circle, and may still be …’ I made it sound as if I was musing to myself.

‘She will stay with us,’ Gratus murmured, as if he too were talking aloud to himself. ‘I have the bed made up already …’ Then he enjoyed telling me: ‘Galla Simplicia and my master are first cousins.’

I offered my hand formally and shook his. It was acknowledgement for this help, while indicating I could not possibly offend him with anything so uncouth as a bribe.

Gratus definitely knew Polycarpus was about to steal his job. He was still a slave; there would be nothing he could do about it. I wished I knew someone in need of a good household steward to whom I could recommend him.

I had had a busy day. Returning to the Aviola apartment, I felt in no mood to prepare detailed notes for Manlius Faustus, but Dromo was hanging about expectantly, wanting to take my report.

First I found my oil flask and went out to some nearby baths, taking Dromo too. There was just time for me to have a quick wash and scrape in the women’s hour, then when the bell rang to announce men’s time I waited in a colonnade, scrawling brief notes for the aedile, while the messenger washed. I had promised him a cake, and was true to my word.

Dromo still smelt – of more than chopped nuts and custard.

‘How many tunics do you have, Dromo?’

‘One.’

I added a postscript to my notes: kindly supply your stinky boy with a spare garment! Please treat as urgent and make sure it has been laundered. Do this for me, most admirable Tiberius, so I can apply myself with a clear mind to the monster ex-wife. Should be good value. You know you want details.

I had no idea whether Faustus enjoyed gossip. If not, I could teach him. All you need is curiosity and a sense of humour. He had those.

Dromo sauntered off with my report, slavering over his pastry and getting custard on the note tablet.

I took a layered date-slice back with me to the apartment. Why should a slave have all the treats?

On the way I bought a hot pie too. This is not good nourishment, but the informers’ creed says the demands of our work compel us to live off unsuitable street food and large amounts of drink. Our life is hard. Some really like to suffer, so they attend experimental harp concerts or dangerous political readings, but after a day’s serious investigating, you risk falling asleep and wasting the ticket price.

I bought a flagon of cheap wine. You have to keep up the image.