She behaved as if she had not heard. ‘Galla Simplicia’s cousin was going to have Cosmus picked up for me, and sent away for sale. I had said nothing about it, but I think Cosmus may have guessed the plan.’

‘It seems unlikely he will come home this time!’ I returned dryly. ‘And that’s good, because you don’t want him in your house with young children here; you must feel unsafe yourself. I have to report him as a runaway, you understand why. The vigiles must set up an urgent search.’

‘Yes. Yes, I understand,’ Graecina agreed miserably. There were tears in her eyes. She was a strong woman but she felt extremely anxious. I did not blame her. Her little household had fallen to pieces. Until the slave was found, there were also grave dangers.

I gave my verdict: ‘I believe your slave Cosmus killed Valerius Aviola and Mucia Lucilia.’ Graecina let out another tiny whimper. She knew it was true. ‘He must have strangled them with the dog lead that has disappeared.’ I knew Polycarpus removed it from around Mucia’s neck – ‘an act of respect for the dead,’ according to Titianus. Trust him to misinterpret. It was ‘respect’ that allowed Polycarpus quietly to remove this murder weapon from the scene, so it would not be identified. Later, he destroyed it or lost it altogether.

As Graecina’s hand flew to her mouth to smother her horror, I had to say, ‘I have no time now to ask, but I find it hard to see why Polycarpus was shielding the boy.’

‘Just kind-heartedness, Albia!’

‘Well, it rebounded. When you and I went into that lock-up, you must have realised straightaway what the boy had done to Polycarpus. Cosmus showed no gratitude for your husband’s protection of him. Cosmus went into the shop downstairs and had an argument. Then Cosmus murdered your husband, strangling his kind master with his bare hands.’

‘I know why,’ admitted Graecina. ‘My husband had a great sense of fellow-feeling for all the slaves in the household, but he knew he now had to stop shielding Cosmus. He refused to keep him any longer after what the boy did to the master and mistress. He said we would sell Cosmus. Polycarpus had to think about me and the children. Cosmus became very angry. He swore he would run away for good. He demanded some of that silver to take with him.’

‘That must have been the quarrel in the lock-up,’ I reckoned. ‘Polycarpus had already hidden the silver elsewhere. He may have refused to say where it was, and he refused to give Cosmus anything.’

I would have liked to ask more questions, about how and why, but Graecina was too upset. Telling her to keep the door bolted, I left her with her sweet little children and her flea-ridden dog.

I had other things to do.

54

I almost ran down several flights of stairs.