A gruff Scottish consultant was called in from his game of golf in Surrey to try and stitch her up. ‘You’ve been a very silly lassie,’ he said. ‘And I’m afraid you’re going to pay for it for the rest of your life.’ He didn’t tell the police though, he might have been dour but he had a heart.

She had told Ian she could never conceive, it seemed only fair. She told him that it was ‘a plumbing problem’, a defect, and he said, ‘Which doctors have you seen, which consultants?’ and she said, ‘The best. In Switzerland,’ and when he said, ‘We’ll consult more,’ she said, ‘Please don’t push me to see any more, darling, I can’t bear it.’ He was older than her by quite a bit, said he always thought he would have a son, teach him cricket and so on. ‘You should marry someone else,’ she told him on the eve of the wedding, and he said, ‘No.’ He was willing to sacrifice everything for her, even children.

‘Are you all right up there?’

‘Sorry, darling, got distracted, started tidying the drawers. Just coming.’ Kitty Winfield rose from her dressing table and rejoined her husband. Before she did so, the doorbell rang. She checked her watch, lovely delicate gold one that was her Christmas present from Ian. (No engraving.) Nearly nine o’clock. They never had visitors at this hour. She looked over the banister on the landing as he opened the door, letting in a huge draught of icy March air.

‘Good God,’ she heard Ian say. ‘What’s happened, Ray?’

Kitty Winfield tripped lightly down the stairs. Ray Strickland was standing on the doorstep, holding a little child in his arms.

Walking the dog swallowed up more time than Jackson had expected. By the time they returned to the hotel and he had showered off the previous night’s evidence he found himself running late and had to leave the hotel again in haste. He realized that he would have to take the dog with him, he could hardly leave it to be discovered by someone coming in to clean the room. A ‘maid’. An old-fashioned word. A servant, a virgin. His sister had been a maid. A young maid. She belonged to another time when girls kept their maidenhood like a treasure.

He unzipped the rucksack and said, ‘Come on, get in,’ to the dog. Jackson hadn’t realized that dogs could frown.

Jackson’s mouth felt as if a mouse had nested in it overnight. Several mice possibly. There was a mirror in the lift and on the way down to the lobby Jackson contemplated his somewhat dissipated reflection for the second time that morning. He couldn’t imagine that it would make a good impression on Linda Pallister. (‘When did you worry about making a good impression?’ he heard Julia say. The one who lived in his head.) It was only quarter to ten in the morning and yet the day already felt as if it had been going on too long. The woman in a management suit on duty at the concierge’s desk gave him a suspicious look as he exited the lift. He gave her a little Queen Mother wave. She frowned at him.

A takeaway bacon roll from a greasy spoon on the short walk from the Best Western helped to perk him up a little. He tore off a piece and posted it into the rucksack for the dog.

Hope McMaster had been silent through his Greenwich mean time night, which was her New Zealand day. If Linda Pallister couldn’t enlighten him about Hope McMaster’s origins then he had no idea what path to take next. A family tree was a fractal, its branches dividing endlessly. Julia, being from middle-class stock, could trace her family back to the Ark but for Hope McMaster there weren’t even bare roots.

A young woman, a secretary maybe, her function was unclear, appeared and said, ‘Mr Brodie? My name’s Eleanor, I’ll show you to Linda’s office.’ This was an improvement. He hadn’t got past reception yesterday before being told that Linda Pallister wasn’t available to see him. Eleanor had a plain face and limp hair that looked as if it resisted styling. And a fantastic pair of legs that seemed wasted on her. Just observing, not judging, Jackson said silently in his defence against the monstrous regiment.

He was carrying a folder. He had bought it yesterday in a pound shop. Way back in his days as a military policeman Jackson had learned that carrying a folder could convey a certain official authority, even, occasionally, menace. In interrogations it implied you had a cache of knowledge about a suspect, knowledge that you were about to use against them. Not that Linda Pallister was a suspect, he reminded himself. And they definitely weren’t in the army any more, he thought as he followed Eleanor’s shapely pins down a corridor. The folder was plastic, a lurid pink neon not found in nature that detracted somewhat from any authority invested in it. It contained nothing even vaguely official, only a flimsy National Trust guide to Sissinghurst and an estate agent’s details for a thatched cottage in Shropshire that had briefly, very briefly, tickled his fancy.

Eleanor was the chatty sort, Jackson noticed rather wearily – lack of coffee was beginning to take its toll on him. She stopped outside a door and knocked on it. When there was no answer she said loudly, ‘Linda? Mr Brodie’s here to see you.’

Absence of Linda left Eleanor at a loss as to what to do with him and Jackson said, reassuringly, ‘Don’t worry about me, I’ll wait outside her office.’

‘I’ll try and find Linda,’ she said, scurrying off.

Twenty minutes later and there was no sign of either Linda or Eleanor. Jackson thought there would be no harm in having a quick look inside the mysteriously absent Linda Pallister’s office. He carried the authority of the folder, after all.

It was a mess. Her desk was home to a jumble of things – clumsy ornaments that seemed to have been made by children, pens, paperclips, books, paperwork, a Marks & Spencer sandwich, as yet unopened, although the date on it was yesterday’s. There were haphazard stacks of paperwork and folders everywhere. She didn’t seem like the tidiest of people.

The sandwich was sitting next to an open appointments diary. All Linda Pallister’s meetings for today, including his own, were crossed out, which didn’t seem like a good sign. He flipped back through the diary, idly, not looking for anything (‘Stop snooping through my stuff !’ Marlee had yelled at him when she caught him looking through her diary).

Yesterday, the two o’clock appointment that she had cancelled with him (‘J. Brodie’) was duly crossed out, as was every appointment after ‘B. Jackson’ at ten o’clock. It seemed an odd coincidence of names. The two Jacksons. Was she confused or had this other, earlier Jackson upset her so much that she started cancelling everything?

When Jackson made the first appointment with Linda Pallister he had spoken with her on the phone. He didn’t say he was a private detective, because he wasn’t, he insisted to himself. It was just this one case. (‘A specious argument,’ he imagined Julia saying.)

At first, Linda Pallister sounded perfectly normal, pleasantly efficient – a demeanour at odds with the state of her office. The mention of Hope McMaster’s name didn’t change things – Hope had already been in email contact with her over her missing birth certificate – nor the names John and Angela Costello, but when he mentioned Dr Ian Winfield she seemed to be thrown completely off balance.

‘Who?’

‘Ian and Kitty Winfield,’ Jackson said. ‘He was a consultant at St James’s. She was a model, Kitty Gillespie. They were Hope McMaster’s adoptive parents.’

‘They—’ she began to say and then clammed up. Jackson had been intrigued but assumed whatever the confusion was it would be cleared up when he met Linda Pallister. He was hoping, for example, that she was going to be able to explain why John and Angela Costello didn’t exist.

Hope McMaster had pulled a thread and everything she had believed about the fabric of her life had started to unravel. But I must have come from somewhere, she wrote. Everyone comes from somewhere! Jackson thought that perhaps it was time to ditch the exclamation marks, they were beginning to sound like notes of panic. Despite her breeziness it seemed that she had begun to struggle with existentialist musings about the nature of identity – Who are we, after all? A nugget of suspicion, that was all it took, until it had nibbled quietly away at everything you believed in.