When it came right down to it, though, Banks had a gut feeling that it was the Mad Hatters story that got Barber killed. He had no idea why. Unless you were a soul or a rap artist, music was generally a murder-free profession, and it was a bit of a stretch to imagine aging hippies going around bashing people over the head with pokers. But there it was. Nick Barber had headed to Yorkshire in search of a reclusive ex-rock star, had found him, and within days he had turned up dead, all his notes, mobile phone and laptop computer missing.

Banks thanked Butler for his time and said he might be back with more questions. Butler accompanied him back to the lift, stopping to pick out some back issues for him on the way. Banks walked out onto busy Oxford Street a little more enlightened than when he had entered Mappin House. He noticed that he was standing right outside HMV, so he went inside.

Monday, 15th September, 1969

The mood in the Grove was subdued that Monday evening. Somebody had turned out all the electric lights and put candles on every table. Yvonne sat at the back of the small room, near the door, with Steve, Julie and a bunch of others. McGarrity was there, though thankfully not sitting with them. At one point he took the stage and recited a T. S. Eliot poem. That was typical of him, Yvonne thought. He dismissed everybody else’s poetry, but didn’t even have the creativity to make up his own. There was a bit of talk about a concert in Toronto that Saturday, where John Lennon and Yoko had turned up to play with some legendary rock ’n’ roll stars, and some desultory conversation about the Los Angeles murders, but mostly people seemed to have turned in on themselves. They had known the previous Monday that something had happened at Brimleigh, of course, but now it was all over the place – and the victim’s name had been in that morning’s paper and on the evening news. Many people had known her, at least by name or by sight.

Yvonne was still stunned by the signed Mad Hatters LP her father had given her before she went out that evening. She couldn’t imagine him even being in the same room as such a fantastic band, let alone asking them to sign a copy of their LP. But he was full of surprises these days. Maybe there was hope for him yet.

McGarrity’s Eliot travesty aside, most of the evening was given over to local folksingers. A plump short-haired girl in jeans and a T-shirt sang “She Walks Through the Fair” and “Farewell, Farewell.” A curly-haired troubadour with a gap between his front teeth sang “The Trees They Do Grow High” and “Needle of Death,” followed by a clutch of early Bob Dylan songs.

There was a somber tone to it all, and Yvonne knew, although it was never said, that this was a farewell concert for Linda. Other people in the place had known her far better than Yvonne had; in fact she had sung there on more than one occasion when she visited her friends in Leeds. Everybody had looked forward to her visits. Yvonne wished she could be like that, the kind of person who had such a radiant spiritual quality that people were drawn to her. But she also couldn’t forget that someone had been drawn to kill her.

She remembered the photograph that had slipped out of her father’s briefcase: Linda with an expressionless face and eyes. The pathetic little cornflower on her cheek; Linda not at home; dead Linda, just a shell, her spirit soared off into the light. She felt herself well up with tears as she thought her thoughts and listened to the sad songs of long ago, ballads of murder and betrayal, of supernatural lovers, metamorphoses, disasters at sea and wasted youth. She wasn’t supposed to drink, but she could easily pass for eighteen in the Grove, and Steve brought her drinks like Babycham, Pony and Cherry B. After a while she started to feel light-headed and sick.

She made her way to the toilet and forced her finger down her throat. That helped. When she had finished she rinsed her mouth out, washed her face and lit a cigarette. She didn’t look too bad. On her way out she had to squeeze past McGarrity in the narrow corridor, and the look of cruel amusement on his face at her obvious discomfort frightened her. He paused, pressed up against her breasts, ran one dirty, nail-bitten finger down her cheek and whispered her name. It made her shiver.

When she got back to Steve and the others, it was intermission. She hadn’t brought up the subject of Linda with Steve yet, partly because she was afraid that he might have slept with her, and that would make Yvonne jealous. It shouldn’t. Jealousy was a negative emotion, Steve always said, to be cast aside, but she couldn’t help it. Linda was so perfect, and beside her Yvonne felt like a naive awkward schoolgirl. Finally, she made herself do it.

“Did you know Linda well?” she asked him as casually as possible.

Steve rolled a cigarette from his Old Holborn tin before answering. “Not really,” he said. “She’d gone before I came on the scene. I only saw her a couple of times when she came up from London and stayed at Dennis’s.”

“Bayswater Terrace? Is that where she lived?”

“Yeah. Before she went to London.”

“With Dennis?”

“No, not with him, just at his pad, man.” Steve gave her a puzzled look. “What does it matter, anyway? She’s dead now. We have to let go.”

Yvonne felt flustered. “It doesn’t. It… I mean… I only met her once, myself, and I liked her, that’s all.”

“Everybody loved Linda.”

“Not everybody, obviously.”

“What do you mean?”

“Well, somebody murdered her.”

“That doesn’t mean he didn’t love her.”

“I don’t understand.”

Steve stroked her arm. “It’s a complicated world, Von, and people do things for many reasons, often reasons we don’t understand, reasons they don’t even understand themselves. All I’m saying is that whoever did it didn’t necessarily do it from hatred or jealousy or envy, or one of those other negative emotions. It might have been from love. Or an act of kindness. Sometimes you have to destroy the thing you love the most. It’s not for us to question.”

Yvonne hated it when he talked down to her like that, as if she were indeed a silly schoolgirl who just didn’t get it. But she didn’t get it. To her, Linda had been murdered. No amount of talk about killing for love or kindness made any sense. Perhaps it was because she was a policeman’s daughter, she thought. In which case she had better stop sounding like one, or they would be onto her in a flash.

“You’re right,” she said. “It’s not for us to question.”

And the second half of the evening started. She could see McGarrity through the crowds, a dark shadow hunched in the candlelight, just to the right of the stage area, and she thought he was staring at her. Then a young man with long blond hair climbed on the tiny stage and began to sing “Polly on the Shore.”

In a booth in a noisy and smoky Italian restaurant on Frith Street, Banks and Annie shared fizzy water and a bottle of the house red, as Banks tucked into his veal marsala and Annie her pasta primavera. Outside, darkness had fallen and the streets and pubs and restaurants of Soho were filling up as people finished work, or arrived in the West End for an evening out. Red and purple lights reflected in the sheen of rain on the pavements and road.

“You’ve got a lot of explaining to do,” Annie said, fixing her hair behind her ears so it didn’t get in her mouth while she ate.

“About what?” said Banks.

“This Mad Hatters business. I hardly understood a word of what you were talking about before dinner.”

“It’s not my fault if your cultural education is severely lacking,” said Banks.

“Put it down to my callow youth and explain in words of one syllable.”

“You’ve never heard of the Mad Hatters?”