“Dad,” said Brian, putting packages on the table, “we went to York for the day. We didn’t know if you were going to be here, so we picked up an Indian take-away. There’s plenty if you want to share.”

“No, thank you,” said Banks, trying not to imagine what seismic reactions might occur in his stomach when curry met Amarone. “I’m not really hungry. I had a sandwich earlier. How did you enjoy York?”

“Great,” said Emilia. “We did all the tourist stuff. You know, toured the Minster, visited Jorvik. We even went to the train museum.”

“You took her there?” Banks said to Brian.

“Don’t blame me. It was her idea.”

“It’s true,” Emilia said, taking Brian’s hand. “I love trains. I had to drag him.”

They both laughed. Banks remembered taking Brian to the National Railway Museum, or York Railway Museum, as it was then known, on a day trip from London when he was about seven. How he had loved climbing all over the immaculate steam engines and playing at being the driver.

Brian and Emilia ate their curry at the kitchen bench while Banks sat sipping his wine and chatting with them about their day. When they had finished eating, Brian tidied up – an oddity in itself – then said, “Oh, I forgot. I bought you a present, Dad.”

“Me?” said Banks. “You shouldn’t have.”

“It’s not much.” Brian took an HMV bag from his backpack. “Sorry, I haven’t had a chance to wrap it properly.”

Banks slipped the case out of the plastic bag. It was a DVD: The Mad Hatters Story. Judging by the account on the back of the box, it contained footage from every stage of the band’s career, including the earliest lineup with Vic Greaves and Robin Merchant. “Should be interesting,” Banks said. “Do you want to watch it with me?”

“I wouldn’t mind.”

“Emilia?”

Emilia took a book out of her shoulder bag, Reading Lolita in Tehran. “Not me,” she said with a smile. “I’m tired. It’s been a long day. I think I’ll go to bed and read for a while and leave you boys together.” She kissed Brian, then turned to Banks and said, “Good night.”

“Good night,” Banks said. “Look, before you go, would the two of you like to come out for Sunday lunch with Annie and me tomorrow? If we can get away, that is?”

Brian raised his eyebrows and looked at Emilia, who nodded. “Sure,” he said, then added with the weight of many broken engagements, “if you can get away.”

“I promise. You are staying a while longer, aren’t you?”

“If that’s okay,” said Brian.

“Of course it is.”

“If we’re not cramping your style, that is.”

Banks felt himself blush. “No. Why should you…? I mean…”

Emilia said good night again, smiled and went upstairs. “She seems like a nice girl,” he said to Brian when she was out of earshot.

Brian grinned. “She is.”

“Is it…?”

“Serious?”

“Well, yes, I suppose that’s what I meant.”

“Too early to say, but I like her enough that I’d hurt if she left me, as the song says.”

“Which song?”

“Ours, idiot. The last single.”

“Ouch. I don’t buy singles.”

“I know that, Dad. I was teasing. And it wasn’t even for sale on a CD. You had to download it from iTunes.”

“Hey, wait a minute. I know how to do that now. I’ve got an iPod. I’m not a complete Luddite, you know.”

Brian laughed and grabbed a can of lager from the fridge. Banks refilled his glass and the two of them went into the entertainment room.

The DVD started with manager Chris Adams giving a potted history, then segued into a documentary made up of old concert footage and interviews. Banks found it amusing and interesting to see the band members of thirty-five years ago in their bell-bottoms and floppy hats manage to sound pretentious and innocent at the same time as they spoke about “peace and love, man.” Vic Greaves, looking wasted as usual in a 1968 interview, went off at a tangent punctuated with long pauses every time the interviewer asked him a question about his songs. There was something icily detached and slightly more cynical about Robin Merchant, and his cool, practical intelligence often provided a welcome antidote to the vapid and meandering musings of the others.

But it was the concert footage that proved most interesting. There was nothing from Brimleigh, unfortunately, except a few stills of the band relaxing with joints backstage, but there were some excellent late-sixties films of the band performing at such diverse places as the Refectory at Leeds University, Bristol’s Colston Hall and the Paradiso in Amsterdam. At one of the gigs, an outrageously stoned and enthusiastic MC yelled in a thick cockney accent, “And now, ladies and gentlemen, let’s ’ave a ’uge ’and for the ’ATTERS!”

The music sounded wonderfully fresh, and Vic Greaves’s innocent pastoral lyrics had a haunting and timeless sadness about them, meshing with his delicate, spacey keyboards work and Terry Watson’s subtle riffs. Like many bass players, Robin Merchant just stood and played expressionlessly, but well, and like many drummers, Adrian Pritchard thrashed around at his kit like a maniac. Keith Moon and John Bonham were clearly big influences there.

There was something a bit odd about the lineup, but Banks was only half watching and half talking to Brian, and the next thing he knew, both Vic Greaves and Robin Merchant were gone and the lovely, if rather nervous, Tania Hutchison was making her debut with the band at London’s Royal Festival Hall in early 1972. Banks thought about his meeting with her the other day. She was still a good-looking woman, and he might have fancied his chances, but he thought he had alienated her with his probing questions. That seemed to be the story of his life, alienating women he fancied.

The documentary went on to portray the band’s upward trajectory until their official retirement in 1994, with clips from the few reunion concerts they had performed since then, along with interviews from an older, chain-smoking, short-haired Tania, and a completely bald, bloated and ill-looking Adrian Pritchard. Reg Cooper and Terry Watson must have declined to be interviewed because they appeared only in the concert footage.

When the film came to a sequence about disagreements within the band, Banks noticed Brian tense a little. Since the investigation had taken him farther into the world of rock than he had ever been before, he had thought a lot about Brian and the life he was living. Not just drugs, but all the trappings and problems that fame brought with it. He thought of the great stars who had destroyed themselves at an early age through self-indulgence or despair: Kurt Cobain, Jimi Hendrix, Tim Buckley, Janis Joplin, Nick Drake, Ian Curtis, Jim Morrison… the list went on. Brian seemed all right, but he was hardly likely to tell his father if he had a drug problem, for example.

“Anything wrong?” Banks asked.

“Wrong? No. Why? What could be wrong?”

“I don’t know. It’s just that you haven’t talked about the band much.”

“That’s because there’s not much to say.”

“So things are going fine?”

Brian paused. “Well…”

“What is it?”

He turned to face Banks, who turned down the DVD volume a notch or two. “Denny’s getting weird, that’s all. If it gets much worse, we might have to get rid of him.”

Denny, Banks knew, was the band’s other guitarist/vocalist, and Brian’s songwriting partner.

“Get rid of him?”

“I don’t mean kill him. Honestly, Dad, sometimes I wonder about the effect your job has on you.”

So do I, Banks thought. But he also thought about killing off disruptive band members – Robin Merchant, for example – and how easy it would have been, just a gentle nudge in the direction of the swimming pool. Vic Greaves had been disruptive, too, but he had made his own voluntary exit. “Weird? How?” he asked.

“Ego, mostly. I mean he’s getting into really off-the-wall musical influences, like acid Celtic punk, and he’s trying to import it into our sound. If you challenge him on it, he gets all huffy and goes on about how it’s his band, how he brought us together and all that shit.”