She went downstairs once more and shook a small amount of cat food into the bowl and put it on the floor. When the cat had finished eating, it left through the cat flap without a backward glance. She washed the bowl and placed it on the rack where she had found it. Then she turned off the torch, put it back into the drawer and then, just as she was opening her front door, she saw something that, for a moment, stopped her in her tracks, her skin prickling. There was a table just inside the door where she put mail and keys. On it was a small metal box she didn’t recognize, about the size of a thick book. A red light flashed intermittently. It wasn’t hers. It was obviously a sort of camera or sensor and, of course, the police had put it there, as she should have known, if she had thought about it, that they would. Put it there just in case she was stupid enough to come back. She had been stupid enough. She had been so careful and now, with one stroke, she was visible again. She quickly left the house, double-locking it behind her.

But she hadn’t finished yet. She walked through Holborn and then along Rosebery Avenue and left up smaller streets until she came to Sandy’s flat. This, too, she knew to be recklessly foolish. She had learned her lesson and she didn’t even try to go inside, simply put the Chubb key into the front door and felt it fit and turn. She pulled it out again and put it back into her pocket, then turned away and left. So Bridget had Sandy’s keys, and she had Frieda’s keys as well.

From Islington to Elephant and Castle was a walk she knew well, the first part at least, following the course of the buried, lost, forgotten Fleet River down Farringdon Road to the Thames, then across Blackfriars Bridge. She stopped to lean over the bridge, as she always did, to see the swirling currents of the great river, as if it were fighting against its own flow. Then she turned south and, though it was the middle of the night, there were still people around and taxis and buses and vans. There was never an escape from all of that. It was nearly dawn before she lay down on the narrow bed and closed her eyes and did not sleep.

20

Frieda was woken by her phone. For a moment, she was disconcerted because so very few people had her phone number. She lifted it up and saw it was Bridget.

‘Sorry to ring so early.’

‘That’s all right.’

‘I wanted to catch you. We’ve got the morning off, so we thought we’d take the children to the zoo. So you needn’t come in until about one, or half past. Sorry about the late notice.’

‘That’s fine.’

‘We’ll pay you anyway.’

‘It doesn’t matter.’

‘Well, we can argue about that when we meet.’

Frieda looked at her watch. Ethan was with Sasha today and she had four clear hours. It was a chance she might never get again. Within five minutes, she was washed and dressed. As she was opening the front door, she heard a hiss behind her. She turned round. It was Mira.

‘You take the potato?’ she said. ‘The salad.’

‘What?’ said Frieda. ‘No, I wasn’t here.’

‘Ileana,’ said Mira, darkly.

‘I’ll buy some food while I’m out,’ said Frieda. ‘I’ll make a meal.’

‘Thieves,’ said Mira.

‘What?’

‘Thieves and gypsies. All of them.’

‘All of what?’

‘The Romanians.’

‘Where are you from?’

‘Ruse.’

‘I don’t know where that is.’

‘It is Bulgaria.’

Frieda felt in her pocket and took out a twenty-pound note. She handed it to Mira. ‘That can go towards food and whatever. And you don’t mean that about gypsies and thieves.’

‘Lock your door,’ said Mira.

‘There isn’t a lock on it.’

‘That is your problem.’

‘Later,’ said Frieda, opening the door.

In another five minutes she was on the bus with a black coffee. She sat upstairs looking at people heading to work or to the shops. More and more she felt different from all that, all the people in the real world of jobs and houses and attachments, people with places to go, appointments to keep. She felt the same estrangement when she opened the door of the house. It felt as if the family had been snatched away in an instant, leaving toys scattered where they had fallen, mugs and plates on the kitchen table. The house still smelt of the people who had left, the coffee, the perfume, soap, skin cream, talcum powder.

She thought for a moment, and then began to walk from room to room, the kitchen and the living room and upstairs to Bridget’s den and the bedroom. The house felt familiar to her now and she had already searched these rooms. She had opened the drawers and the cupboards. She paused in the bedroom and looked out of one of the large windows that faced the street. An idea had occurred to her: it was somewhere in her mind but she couldn’t quite grasp it. What was it? Let it go. Her rummaging and searching had produced nothing so far. Nothing except the keys. They had the keys to Sandy’s flat and they had the keys to her house. Suddenly the idea came to her. She ran down the stairs two at a time. The device at her house, inside the door. How could she be so careless a second time? She looked at the alarm inside the front door. It was switched off. Frieda felt a sudden jolt of alarm. Was it possible that someone was still in the house? Could Al be on the top floor? No, she told herself. They’d just forgotten to turn on the alarm.

But the idea of Al stayed with her. Frieda had mainly been thinking about Bridget, that she might have had an affair with Sandy. Somehow she seemed like Sandy’s type, maybe more his type than Frieda had been. But Al was his colleague and his friend. Had he suspected something, known something? The rooms she had looked at so far had felt like Bridget’s territory, even the shared bedroom. But she had never been to the top of the house. She walked back up the stairs, past the bedroom, up to the next floor. She knew better, but even so she walked as quietly as she could. The stairs ended in an attic room that had been converted into an office. On the side away from the street there were two large skylights. Frieda walked across and looked out. She could see the Shard and the Gherkin and the Cheese Grater, those big buildings with silly names, as if London were slightly ashamed of them.

She turned to the room. In the centre was a large pine desk, with a computer surrounded by piles of papers and cards and CDs. There was a mug full of pens and a cup containing paperclips. There was a wooden pencil box, two toothbrushes, a Flash drive, a compass, a watch, an energy bill, two pairs of headphones and a small framed photograph of the children. There were books everywhere, on makeshift wooden shelves on two of the walls, stacked on the floor. There were also piles of different scientific journals. On another table there was a CD player and more piles of CDs, a shredder, an empty magnum-sized bottle of wine and a tangle of cables and chargers. On one space of bare wall there was a messy watercolour, presumably painted by Tam, and a photograph of Al crossing the line in the London Marathon. Frieda leaned in close and looked at the time: 04.12.45. Was that good?

Frieda pulled open the drawers of the desk one by one. There was nothing unexpected: chequebooks, blank postcards, a stapler, Sellotape. Another drawer contained a pile of credit-card statements. Frieda scanned them quickly: petrol, railway tickets, a supermarket, coffee, a couple of cinema visits, names that were probably restaurants. Frieda put them back. She didn’t even know what she was looking for. Another drawer contained cardboard files. Frieda took them out one by one and riffled through them. They looked like lectures, presentations, chapters of a book. Frieda replaced them in the order she’d taken them out and turned her attention to the computer.