‘Then Dromo will go to the fountain and fetch more. Dromo, arm yourself with buckets from the kitchen. Better bring an extra one for Flavia Albia, in case we are due for an up-chuck.’

‘Not me.’

‘Shall we take bets?’ growled Faustus, at his most disparaging. ‘Just don’t heave your heart out on me, will you?’

I maintained that I would not dream of vomiting on him since the tunic he was wearing was bound to be his favourite, one woven by his grandmother with her own hands. (He was in his aedile’s white and purple, so I knew the tunic was not old. On the other hand, it was expensive and must require high-price laundering.)

The brute snorted.

Although my head was spinning, I refused offers of help to reach my room. I must have had the kind of exaggerated dignity that tells people you are on the verge of losing all your grace and elegance, but I summoned up enough willpower to stalk indoors. That may have confirmed to the aedile that I had been drunk in the morning on other occasions.

I heard them leave. I felt desperate to collapse upon the bed. However, that would have meant crushing the loaf I bought all that time earlier for the breakfast I had never eaten. Stale crumbs are painful to lie on.

I knew what to do. I tore it into its segments and ate the loaf now. All eight pieces. I chewed carefully to lessen the chance of what Tiberius had called up-chuck.

There was an experiment that I had to try. I could ask the aedile and Dromo to help, but I didn’t want to look foolish if my suspicions were wrong. If I was right, I wanted the heaviest possible impact. When dealing with theories, I follow the good informer’s rule: mull it over; test it for yourself; be certain of the answer; then bedazzle your client.

Action.

When I walked back out into the courtyard, I groaned. It was now midday, with the sun right overhead. I covered my eyes against the fierce glare of warm light in that bare space. I stood for a while, swaying gently.

Forcing myself to move, I walked over to the well in the corner. It had been boarded over with a set of wide planks, butted up against one another. Someone did a neat job. I pulled up one of the edge planks, which were smaller, trying not to get splinters as I held the end, then turned it as I heaved it over away from me. The top must have been scrubbed. The underside no one had bothered to clean. There the wood was covered with dark, rust-coloured stains, which I knew must be dried human blood.

‘As I thought! Well done, Albia.’