As Wada continued to delve, she came upon a Kodak-yellow wallet of photographs, slipped in between the documents about halfway down the box. She lifted out the wallet and opened it. There was a sheaf of snapshots, their colour slightly faded. Judging by the age of the people in the pictures and the seventies style of their clothes and hair, Wada reckoned they were snaps of Caldwell and his friends from university days – members of the commune, perhaps, that Joan had said lived in the house when he was a student at the university. On that basis, one of them could be Peter Evans. But which one it was impossible to say.

Some of the pictures had obviously been taken in the garden of 18 Barnfield Hill. Wada recognized the house in the background. In one a group of eight was standing outside the front door: four young men, four young women. One of the women was spectacularly beautiful, with flowing blonde hair and a direct, luminous gaze. The others were attractive in their youthful way, but she stood out as someone apart. She appeared in several of the pictures, including the half-dozen or so taken at a beach party, where the light was softer and thinner with each shot, as evening advanced, somewhere long ago on a broad sandy shore.

Wada suddenly noticed an object that had been slipped into the wallet along with the photographs. To her surprise, she found it was a computer stick. There was a tiny label stuck to it, on which was written, in a minute hand, facetrail.

Wada was squinting at the word in bemusement when the telephone started ringing, so loud in the silence of the flat that it made her jump. She turned and looked across at it. What to do? Let the caller leave a message? She waited for the answerphone to kick in.

But she changed her mind before it did. Slipping the computer stick into her trouser pocket, she moved across the room to the desk and picked up the phone.

She didn’t speak. At first, neither did the caller. Then there came a male voice at the other end of the line. ‘Martin?’

She didn’t reply.

‘Martin, are you there? This is Nick Miller. What the hell happened yesterday afternoon? Where were you?’

Wada said nothing.

‘Are you going to talk to me, Martin? You said you wanted to. So, what’s the big silence all about?’

Still Wada said nothing.

‘I’m going to hang up, OK?’

‘Don’t,’ Wada said instinctively. She couldn’t let slip the chance of learning something of value from the caller.

‘Who’s that?’

‘Tell me—’ A noise somewhere else in the flat distracted her in that instant, but she decided to press on with the call. ‘Tell me who you are first.’

‘I’ve already given you my name.’

‘How do you know Martin Caldwell?’