‘Not sure. Friday, I think. He’d gone by Saturday. Early start for London, I dare say.’

‘And you have not heard from him since?’

‘Not a word. Though we wouldn’t expect to. He keeps himself to himself.’

‘What does he do for a living?’

‘Well, he used to work for an insurance company. But he retired a few years ago. He keeps busy, though. So he says, anyway. I wonder why he didn’t meet you. He seemed to be looking forward to it. Where can he have got to?’

‘That is a good question.’ Wada managed another sip of tea, aware she was going to have to drink it all before leaving. And aware that the sooner she left the sooner she could try her luck in Caldwell’s flat. ‘I wish I knew the answer.’

It took Wada another half an hour to extricate herself from the Stapletons’ flat. Joan promised to contact her as soon as Caldwell returned and said she would tell him he should contact her himself with an explanation and an apology. Meanwhile, she was very interested in what Wada could tell her about the practicalities of wearing a kimono and was clearly disappointed when Wada said they were completely impractical, which was why she never wore them. ‘But you’d look so lovely in one, dear.’ Really, it was impossible to dislike Joan Stapleton. She and Haha would have got on famously.

Eventually, Wada made an exit, hastened by a telephone call that prevented Joan detaining her further. She waved and smiled as Wada let herself out.

The call was fortuitous. Joan didn’t strike Wada as someone who indulged in brief telephone conversations. Which meant there was no chance of her looking out of the window and being puzzled by not seeing her visitor walk away along the street.

As soon as the door of flat 4 closed behind her, Wada turned and hurried up the stairs leading to number 6.

She moved with a quiet, soft-footed tread as she approached Caldwell’s door. She slid the key into the lock and turned it slowly and carefully, then gingerly pushed the door open. She listened for a moment before stepping inside.

As she closed the door behind her, shutting out the rest of the building, the particular atmosphere of Caldwell’s flat disclosed itself in a succession of sensations. The angle of daylight was different up here, because the windows were dormers. That and the fact that there were no carpets, just rugs of various sizes laid across the floorboards, gave it the feeling of an attic. It wasn’t cluttered or untidy. The place felt both masculine and solitary, but not excessively so. Caldwell was in control of his world.