‘You should have told me.’

‘What? What should I have told you? I don’t understand this.’

‘Why did Sandy have Ethan’s animals? Because he was visiting you? Or because you were visiting him?’

Tears were running down her cheeks. ‘Frieda, don’t look like that.’

‘You and Sandy.’

Sasha put her face into her hands and through her fingers said, in a muffled voice, ‘I wanted to tell you. Every time I saw you, I wanted to. I nearly did so many times. And then when I arranged to meet you in the café – I had made up my mind at last, but you didn’t come.’

‘I wish you had told me, Sasha.’

‘It was only after you weren’t with him. I would never have … Not ever. You have to believe that. And only a few times. Because everything was so awful and he needed comfort and so did I and we both felt terrible after. Terrible. It made everything worse, not better.’

‘When was it?’

‘Why does that matter?’ She was sobbing now. ‘I didn’t do anything to hurt you. He was lonely and in a state and so was I. Don’t be angry with me.’

‘I’m not angry, Sasha. Please tell me when it was.’

‘Months ago. When everything was going wrong with Frank. And then Sandy was almost mad with guilt because he thought he’d betrayed everybody, you, me, Frank, himself, the whole world. He said he had ruined everything he most cared about.’

‘Who knew?’

‘Nobody knew. Not a single person. I swear. Nobody knew.’

‘Somebody knew.’

‘What are you saying?’

‘Nothing. I’m not angry.’ Frieda put a hand on Sasha’s shoulder. ‘You didn’t do anything to hurt me. It’s not your fault.’

‘What isn’t? Where are you going?’

But Frieda kissed her on one cheek, then the other, and left.

Five minutes later, Sasha heard her doorbell ring again and then a violent knocking.

‘Karlsson!’ she said, as she opened the door. ‘What’s the matter?’

‘Have you seen Frieda?’ he asked. He put a hand on her shoulder, gripping it tightly. ‘Tell me the truth now. I need to know.’

‘Yes. She’s only just left.’

‘Where did she go to?’

‘I don’t know. I promise I don’t know.’

‘Do you have a way of contacting her?’

‘No.’

‘Why was she here?’

‘Is it important?’

‘Yes.’

‘All right.’ Sasha lifted her head and met his gaze. ‘She found out I had an affair with Sandy.’

‘With Sandy? How could you?’

‘If was after they split up. But I feel so terrible about it.’

‘Where’s Frank now?’

‘Frank? I don’t know. Maybe at work. He sometimes stays until midnight, working. Or at his place. It’s not his day for Ethan and –’

‘What’s his address?’

‘Ten Rayland Gardens. It’s only a few minutes from here.’

Karlsson was turning to go but Sasha put out a hand and stopped him.

‘Why? What’s happening?’ Her voice had a sob in it. ‘What have I done? He didn’t know. Nobody knew. Karlsson, what’s going on?’

‘I need to go, Sasha. If Frieda comes, tell her to contact me at once, and you call me as well. Even if it’s three in the morning.’ He pulled his card out of his wallet and handed it to her. ‘And if you see Frank, call me directly. Do you hear?’

Sasha started to speak but Karlsson was gone, running down the street, talking into his mobile as he went.

‘Sarah,’ he said. ‘It’s me, Karlsson.’

‘I don’t think there’s anything more to say.’ Her voice was cool. He could hear children’s voices in the background: she must be at home, with her family.

‘You have to listen. This is of vital importance. The man who killed Sandy is called Frank Manning.’

‘Frank Manning?’

Karlsson had to force himself to be calm, to explain to Hussein about Frank’s relationship to Sasha, his knowledge of her affair with Sandy and his grievance against Frieda, how he had threatened Mira and Ileana. Then he gave her Frank’s various addresses and told her he would forward her Frank’s phone number.

‘Where are you going to be?’

‘I need to find Frieda.’

‘Just don’t do anything to fuck this investigation. Anything more.’

He took the card that Frank had given him out of his wallet and texted the number to Hussein. Then he called the number himself, but it went to voicemail and he didn’t leave a message. He looked up Rayland Gardens on his phone. It was just a few minutes’ walk from there. And what else was he going to do?

The pubs were overflowing onto the streets, people standing in groups on the pavements in the evening sun. Karlsson strode rapidly through them. He thought of Frieda that morning, sitting on the hill, her shorn head turned towards him, her bright glance upon him, with London spread out in front of them. Where was she now?

He came to Rayland Gardens and stopped in front of number ten. There was no way of knowing if anyone was in: the curtains were open and there were no lights visible, but it was still quite bright outside. He went to the front door and tried to peer through the mailbox but could see nothing except a small strip of floorboard. At that moment, two cars drew up a few yards up the street and, turning, he saw Glen Bryant get out of the first one. He stood back and watched. Bryant knocked on the door and waited. Nothing. He knocked again, more loudly and for longer. Again, nothing. He saw Bryant take out his mobile and knew he would be calling Hussein. Karlsson was sure that Frank wasn’t there. He turned and walked back down the road with no idea of where he was going or what he should do.

‘“Can’t you sleep, little bear?”’ read Sasha. It was the fourth time she had read the book that evening. It was one of Ethan’s favourites; he liked the words and he loved the pictures, and often he would fall asleep while she was reading it, like the little bear in the book, who is carried out to look at the bright yellow moon. But that evening, Ethan was wide awake. His eyes glittered and there were excited pink spots on his cheeks.

‘Again,’ he said, as Sasha reached the final page.

‘It’s very late. Why don’t you try closing your eyes and I’ll stroke your hair?’

‘Where’s Daddy?’

‘You’ll see him very soon.’

‘Now.’

‘Not now, Ethan. Now it’s night-time. Time for you to go to sleep.’

‘Now!’ repeated Ethan. ‘I see Daddy now.’

‘No, you don’t.’

‘Yes. Yes, I do!’

‘OK. I’ll read you one more story, and then I’m going to turn out the light.’

‘The window.’

‘I’ll leave the curtains a bit open so some light comes in, all right?’ For Ethan hated true darkness.

‘Will he come again?’

‘Who?’

‘Daddy.’

‘Of course. Very soon. Just a day or two.’

‘Not now?’

‘No. Please go to sleep. I’m very tired.’

‘I wanted him to say goodnight to me.’

‘Ethan –’

‘He stood and stood.’

‘Who – Frank?’

Ethan nodded. ‘I waved. He didn’t see me.’

Sasha sat very still on the bed. Then she took one of Ethan’s hands and said in a low voice: ‘Do you mean you saw Daddy tonight?’

Ethan nodded and snuggled against her. ‘In the window.’

‘What was he doing?’

‘Waiting.’

‘Why was he waiting, darling?’

‘For Frieda,’ said Ethan, as if it were obvious. ‘Frieda walked away and then he walked too. I waved and waved but he didn’t wave back. Was it a game?’

But Sasha had gone from the room and she hadn’t even turned out his light.

Karlsson had gone towards Hackney with a miserable feeling of having nowhere to go and nothing to do. He bought a coffee and drank it as he walked south along Kingsland Road, lighting another cigarette. Then his phone rang. It was Hussein. Frank wasn’t at his chambers and he wasn’t at his house. They were widening the search and also getting a warrant. She would let him know what they found.

‘What can I do?’

‘Nothing,’ she replied firmly, but not unkindly. ‘You can do nothing.’

As she spoke a message came up on his screen: there was an incoming call from Sasha. Without saying goodbye, he cut Hussein off and answered. ‘Yes?’