Nathan was following him around, telling him about dinosaurs, barely stumbling over the names, ‘Velociraptor, Avaceratops, Diplodocus.’ Jackson wasn’t sure if his son knew they were extinct, didn’t want to ask him in case he spoiled some kind of mystery, like Santa Claus and the Tooth Fairy. Jackson didn’t know that four-year-old boys could pronounce words like ‘Avaceratops’. He could barely remember Marlee at that age, her current sullen incarnation had begun to dominate earlier, sunnier versions of his daughter. Of course, there were a lot of things he didn’t know about four-year-old boys. He thought of his son as a baby and it was disturbing to see how far along the road to manhood he had already walked. One day that boy would outrun him, overtake him in the relay race of existence. And so it would go on and on until the sun cooled, or the meteor hit, or that bloody great volcano beneath Yellowstone grumbled its way back into life.

‘Well, everything dies,’ Julia said, absorbed in scratching the dog’s belly and staving off a sneeze. ‘That’s the way it goes. Omnia mors aequat. The great leveller.’

‘From darkness we come and to darkness shall we return,’ Jackson said. Darkly.

‘I think it’s dust, not darkness,’ Julia said. ‘And I choose to think that we come from the light and return to the light.’

‘What a glass-half-full kind of person you are.’

‘One of us has to be,’ Julia said. ‘Or the glass would be entirely empty.’ One of us, as if they were a couple. Yet she was going to Italy on holiday, ‘with a friend’.

‘Who?’ Jackson asked and she shrugged and said, ‘Just a friend.’

‘Could you be any vaguer?’

This despite the fact that Jackson had suggested to her that perhaps the three of them might take a holiday together during her time off. A step towards reconciliation, perhaps towards reunion.

‘Like a family holiday?’ she said and Jackson thought about it and said, ‘Yes, I suppose that is what I mean.’ Julia wrinkled her nose and said, ‘No, sweetie, I don’t think so.’

He was surprised at how disappointed he felt. But then women were full of surprises. Every one of them, every which way, every day.

‘Where is Jonathan anyway?’ he asked.

Julia put up a hand as if stopping traffic, as if stopping an enormous towering truck. ‘I’m not speaking about Jonathan. OK?’

‘Happy never to mention his name again, I’m sure.’

‘That poor boy,’ she said, putting her arms protectively around her own boy. Their boy.

‘Michael?’

‘He went through so much.’

‘He’s OK now.’

‘In the same way that you and I are?’ Julia said. ‘After what happened to us when we were children?’

‘Yeah. That way.’

Michael Braithwaite was on his way to New Zealand even as they were speaking. A brother and sister reunion. He was a nice bloke, top-to-toe denim, overweight, unhealthy, cheerful. He liked nothing more than a barbecue with his wife and kids next to his swimming pool. He’d made a fortune in scrap. Some people lived their life against all the odds.

‘You and me too, sweetie,’ Julia said, patting him on the hand.

Linda Pallister had returned to Leeds and was set to appear before a tribunal and be made to answer for her actions. (‘Ah, the whirligig of time,’ Julia said.) She had helped a four-year-old witness to disappear. Put him in a care home in Roundhay run by nuns, changed his name. And never mentioned his sister to anyone. Told the nuns he was a liar, lied all the time, about having a sister, about his dad killing his mum. When Michael was eighteen he was handed his birth certificate and found out his name, but Linda Pallister never came forward and told him the truth about his mother, or his sister. ‘She was coerced,’ Michael Braithwaite said, ‘her own kid threatened.’

‘Not an excuse,’ the two Jacksons said in unison. Brian Jackson, Michael Braithwaite and Jackson were eating lunch in the bistro in 42 The Calls. Jackson, still shaken by the scene on Leeds station, drank a double malt instead of lunch.

Michael Braithwaite’s memories faded until the slate was wiped clean, but he realized there was an emptiness that would destroy him eventually. ‘Therapy in rehab,’ he shrugged. ‘My name is Michael Braithwaite and I’m an alcoholic, all that stuff.’ Guiltily, Jackson put his whisky down. ‘Decided to go looking,’ Michael Braithwaite said.

‘And found me,’ Brian Jackson said, beaming. ‘Twenty years in the Met behind me. Give me a task and I’m like a dog with a bone.’ Jackson had begun to think of Brian Jackson as his doppelgänger – God knows why – but now he could see that really he was his polar opposite. ‘Made an appointment with Linda Pallister, tracked her down,’ Brian Jackson said. ‘Dog, bone, et cetera. She spilled the beans, most of them anyway, seemed keen to get it off her chest. Changed her mind, took fright, of course.’

Brian Jackson’s phone rang – the opening bars of Beethoven’s Fifth, Da-da-da-daa. Sounded naff on a phone. He didn’t answer it. ‘In constant demand,’ he said to Jackson.

Linda Pallister had not been squirrelled away by Brian Jackson. She had, despite her daughter Chloe’s protestations, simply run away. ‘Bolted,’ Brian Jackson said, ‘to avoid facing the music.’ She had caught an easyJet flight to Malaga and hidden herself away like a desperado in a cheap apartment block on the Costa del Sol.

‘It’s all quite banal really, isn’t it?’ Julia said. ‘People frightened of losing their jobs, their reputations, their marriages. You feel that tragedy should be more operatic somehow.’

Jackson’s knee-jerk reaction was to disagree with her but when he thought about it he suspected Julia might be right. His own sister, as beautiful as she was, more beautiful than was possible in his memory, wanted nothing more than the most ordinary of lives and what she got was the most ordinary of murders. A random act of violence. A girl who opened the wrong box. As far as her killer was concerned, Niamh could probably have been anyone – the girl before her, the girl after her. Better to go up in flames at the stake, or jump from a mountain ledge, be torn apart by wolves, rather than have your fate placed in the hands of some wanker waiting at a bus stop.

‘The Ambassador loves having his tummy tickled,’ Julia said.

Jackson was definitely going to give the dog a different name. He wondered what Louise, back in Edinburgh, had called the puppy he had given her. She probably hadn’t even kept it.

‘Where are you going now?’ Julia asked him when he said goodbye to her at security in Manchester airport.

‘Journey’s end,’ he said.

‘In lovers meeting?’

‘I doubt it.’

He was still looking for a new home, he had to lay his head down somewhere every night. He supposed he was still looking for his thieving wife as well, but his enthusiasm for the hunt had cooled. He suspected he might have done with travelling for now. He held Nathan, the boy, in his arms, and kissed him goodbye. And there it was.

To his surprise, to his alarm – the fierce churning of the heart, the unbreakable, sacrificial bond. Love. He knew who he was, he was this boy’s father.

It just went to show, you never knew what you were going to feel until you felt it. It was terrifying, although Julia would have said ‘wonderful’, being the full half of the glass.

‘Stop putting words in my mouth,’ Julia said.

In the security control room at the Merrion Centre, Grant had his feet up, reading the paper instead of watching the screens. Leslie could see the headline in the paper, ‘Leeds prostitute murders – man held for questioning’ and then something about ‘a new Ripper’.

‘It never stops,’ Leslie said.

‘Slappers, what do you expect?’ Grant said, reaching for a packet of Monster Munch.

‘I expect people to behave better.’