‘You do realise, Sara, that excitement of one form can lead to excitement of another. I imagine it would only take him a phone call to summon it.’

‘It’s possible but I don’t believe that’s what happened.’

‘Just suppose it was that, bad as it is,’ said Iona. ‘Might it not be better than the alternatives?’

The doorbell rang, making Iona jump. Sara felt a surge of relief at not having to address the question the widow had left hanging in the air. She returned with the dark-haired daughter, the one with no evidence of marriage from the photographs on the piano.

‘Jennifer, my eldest,’ said Iona. Sara noticed all too easily the split second during which Jennifer was wondering what an Asian woman wearing a scarf was doing in her parental home.

‘I should be leaving,’ said Sara.

‘Yes,’ said Iona, ‘there must be much to do.’ She turned to her daughter. ‘Give me a moment, darling, I’ll see Miss Shah out.’

She led Sara into the hall. ‘Hold on a minute, could you?’

Before Sara had time to answer, Iona was skipping up the stairs. Within a minute she was back, carrying a slim rectangular package wrapped in birthday paper. ‘I’m sure he’d think you must have it,’ said Iona, handing it over. ‘In any case, there’s no one else.’

‘Thank you,’ said Sara. She crammed the package into her bag, shook Iona’s hand and turned towards the front door. As she closed it behind her she saw the widow retreating, relieved of at least one of her burdens.

It had to be.

‘… a final folder of material…’

How had it arrived? Where had she been keeping it? Irrelevant questions. All that mattered was what was in it. Peering up the street at the waiting police car, this was not the time or place to open it and find out.

She felt more exposed and alone than ever. As if to fight it, she walked fast, willing herself to take sharp, deep breaths – to build a flow of oxygen to dispel the smog of doubts and suspicions. She realised the dangers of frenzy and paranoia fuelling conspiracy theories against what had become known as the ‘deep state’. The case of the MI6 man stuffed in a holdall endured so long that it even formed the plot of a television drama where the city lived only by night and an assassin might be waiting around any corner. It was the currency of the age; nothing was allowed to be simple. The problem in the case of Sir Francis Morahan was that nothing was simple. What was it he had said to her when they first met? ‘I’m not a conspiracy theorist. I don’t believe our intelligence services shoot people in the head or drop them out of helicopters.’ Was that because they didn’t need to?