‘I’m very sorry, Mrs Hook,’ said Strike formally, from the doorway into his office. ‘It’s never easy to get news like this.’

‘I th-thought it was Valerie,’ whimpered Mrs Hook, her dishevelled head in her hands, rocking backwards and forwards on the groaning sofa. ‘I th-thought it was Valerie, n-not my own – n-not my own sister.’

‘I’ll get tea!’ whispered Robin, appalled.

She was almost out of the door with the kettle when she remembered that she had left Jonny Rokeby’s life story up on the computer monitor. It would look too odd to dart back to switch it off in the middle of this crisis, so she hurried out of the room, hoping that Strike would be too busy with Mrs Hook to notice.

It took a further forty minutes for Mrs Hook to drink her second cup of tea and sob her way through half the toilet roll Robin had liberated from the bathroom on the landing. At last she left, clutching the folder full of incriminating photographs, and the index detailing the time and place of their creation, her breast heaving, still mopping her eyes.

Strike waited until she was clear of the end of the street, then went out, humming cheerfully, to buy sandwiches for himself and Robin, which they enjoyed together at her desk. It was the friendliest gesture that he had made during their week together, and Robin was sure that this was because he knew that he would soon be free of her.

‘You know I’m going out this afternoon to interview Derrick Wilson?’ he asked.

‘The security guard who had diarrhoea,’ said Robin. ‘Yes.’

‘You’ll be gone when I get back, so I’ll sign your time sheet before I go. And listen, thanks for…’

Strike nodded at the now empty sofa.

‘Oh, no problem. Poor woman.’

‘Yeah. She’s got the goods on him anyway. And,’ he continued, ‘thanks for everything you’ve done this week.’

‘It’s my job,’ said Robin lightly.

‘If I could afford a secretary… but I expect you’ll end up pulling down a serious salary as some fat cat’s PA.’

Robin felt obscurely offended.

‘That’s not the kind of job I want,’ she said.

There was a slightly strained silence.

Strike was undergoing a small internal struggle. The prospect of Robin’s desk being empty next week was a gloomy one; he found her company pleasantly undemanding, and her efficiency refreshing; but it would surely be pathetic, not to mention profligate, to pay for companionship, as though he were some rich, sickly Victorian magnate? Temporary Solutions were rapacious in their demand for commission; Robin was a luxury he could not afford. The fact that she had not questioned him about his father (for Strike had noticed Jonny Rokeby’s Wikipedia entry on the computer monitor) had impressed him further in her favour, for this showed unusual restraint, and was a standard by which he often judged new acquaintances. But it could make no difference to the cold practicalities of the situation: she had to go.