His days are rich. He enjoys the garden, with cricket on the radio. He enjoys a weekly swim at Pells Pool, but only in the summer. Undressing on the grass, he is surprised by the great white mass of his stomach; by the grey hairs webbed against his chest. He is surprised not to sink. In the winters, he hibernates, with biscuits and sports biographies. He talks at local schools and at community centres in London, talking about his time on the beat, talking about his days as a detective, talking about how they could do the same. Some days they will ask interesting questions, and he’ll know that they really listened, that the day was well spent; other times they will enquire: ‘Did you wear a hat?’

Sometimes. He will think of it, then. Sometimes he had returned home in the early morning, his mind crawling with hatred for the human race, and he had contemplated packing a bag and driving to the loneliest place he could think of – Ben Armine, perhaps, or Snowdonia – and spending the rest of his days as a hermit. (Or, he reasoned, as the local eccentric; that way, he could maintain access to hot meals, and a pub.) There had been days when he couldn’t speak to Alice because she was too incompatible with his shift: she believed that people were, fundamentally, good. She sang in the kitchen, and was upset when she received charity leaflets about cruelty to animals. What could he possibly say?

Yes. There had been a time when he had worn a hat.

Many of the cases were solved, and he doesn’t think about them so much. Others hang open, like a door in the winter, and he can feel their draught.

For example: a twenty-year-old man, Freddie Kluziak, attended the party of a close friend in the function room of a pub. Second floor. The pub’s surveillance camera was fixed on the stairs leading up to the party, and captured Freddie ascending with two acquaintances, carrying a birthday present. At the end of the evening, the lights came up, and Freddie’s friends searched for him, to no avail. That was fine: he would have left early, drunk or tired. Two days later, his girlfriend raised the alarm. Nobody had seen him since the party. The surveillance footage arrived on Jameson’s desk like a long-awaited invitation. The whole team gathered around, craning for the details. Jameson spent seventy-two hours accounting for each person who walked up the stairs that day, and each one of them walked back down, except Freddie Kluziak.

What perturbed Jameson the most was the present. That was gone from the scene, too. He felt absurd, telling Freddie’s father that his son must have left via a window with a parcel in his arms, but at that stage they had excavated every wall of the function room, and the landlord was sick to death of them.

Or: a five-year-old child climbed up to a third-floor window ledge and jumped. George Casper was illiterate and near mute. He did not, his teacher explained, know how to turn the pages of a book: he would look at them like they were dead, flat things. He liked birds. This from the mother. Offered as an explanation. George had pushed a chair to the window, she said, to get closer to them. He rolled from the sill, a grubby Icarus, half-naked and with no vocabulary to shout. ‘Which chair?’ Jameson asked, and the mother couldn’t remember; she had moved it to see the body below. Jameson lifted all three chairs in the flat and did not believe that a malnourished child could have moved any one of them. The rooms were a cacophony of DNA: the boy had stood on every seat; there were dregs of each resident in all of the beds; they tested some dog shit in error. Jameson did not know how the child had come to land on the concrete, but he looked at the parents and suspected that they were not just stupid, but cruel.

He was unprofessional, then. The only sordid months of his career. He walked past the door of the flat in jeans and a shirt, after work, listening to the family. He followed the stepfather to a pub and drank six whiskies – six – hoping to hear something before last orders. ‘Where do you go,’ Alice murmured, when he came in smelling of smoke, the folds of casual clothes sounding different from uniform as he undressed in the darkness.

One evening he passed the mother in the forecourt of the block. She was carrying shopping bags and her belly was engorged. It was too late to change direction, so he smiled at her, and she glanced away, then looked back.

‘Aren’t you the policeman?’ she said, eyes roaming for uniform, or a badge.

‘Yes. Yes. Just on a plain-clothes patrol. How are you?’

He carried her bags up the stairs. She was excited to be a mummy again, she said. They came out cute as puppies. ‘Do you have children?’ she asked, and he said no. He hoped to, some day. He wished her good luck.

That night he lay on the bed, fully-clothed, and Alice woke to him crying. The tremble of his body across the mattress. They had wanted a child for five years by then. He gathered her into his arms – maybe it was her gathering him – and his face dried against her hair. It was no good thinking about the unfairness of life, and they had resolved not to do so, but sometimes—

There were other things that they could do. There were children in the family. Alice’s younger brother had three girls, and they looked after them often. Jameson and the eldest girl shared a birthday, and when she was ten he spent a whole day assembling a garden trampoline for the family party, with balloons tied to its legs. It was unexpectedly exhausting, and when he had finished, Jameson collapsed on the mat. Alice stood at the kitchen door, holding her tea, and laughing.

‘Harder or easier,’ she said, ‘than flat-pack furniture?’

She set down her mug on the doorstep and clambered past him, up onto the trampoline. She bounced, threateningly, from foot to foot.