Yet there was even less hint of real affection in her brisk and formal ‘Good morning, my dear Ferox. I trust you are well.’

‘My lady,’ he replied. ‘You are most kind.’ He looked for some sign to show whether she now hated or trusted him, but there was none, only the noble Roman lady and dutiful wife walking beside her husband.

Cerialis hesitated in the doorway, breathed deeply, and then went in. Before Ferox could follow, Lepidina stepped after him.

‘My lady,’ he said, ‘it is probably better if you remain outside.’

She turned, every inch the high and mighty aristocrat. ‘Centurion, I am grateful for your concern for my welfare, but this is my house and I am not one of your soldiers to order as you please.’

Privatus was standing behind her and Ferox saw the chamberlain give an approving nod. The freedman could not see his mistress wink. He hoped that it was a sign of forgiveness and the simple gesture brought memories of the night flooding over him again. Ferox could tell that all his natural suspicion and scepticism would not be enough whenever he was near this woman, for there was something overpowering about her. As he followed her through the door he looked down at her shoulders, the smooth white skin barely covered by her light dress, and he longed to pluck off the brooches holding it up and see it rustle to the floor. As if she could read his mind, the lady turned her head and gave him a cold stare.

The smell brought him fully back to grim reality. There was the usual odour of a bedchamber in the morning, before the slaves had come to empty the vase of night soil. It was the scent of the human body, tinged with sweat, and if this was fainter with a woman it was always there. The damp, musty smell so common at Vindolanda and especially on the ground floor of the praetorium lingered in the background, even when Privatus got a pole and opened the shutters on the high windows, so that bars of sunlight speared into the room.

Over it all was the smell of death: not the violent butcher’s yard stink of the dismembered dogs, but a subtle, insidious cloud that seeped into the nostrils and throat. The girl lay on the bed, and now that the windows gave them more light Ferox could see that what he had taken to be a necklace was a deep cut around her throat. Someone had covered her up in blankets, so that it would look as if the guest was asleep in her bed.

‘It is her maid,’ Privatus told them. ‘Her name was Artemis and she was a silly little thing, but worked hard and was faithful.’

Cerialis sighed. ‘I’ll organise a search. Ferox, would you mind taking a look and seeing if you can work out what happened?’