There had been some serious consequences, family-splitting, relationship-wrecking consequences, and no one had heard from Roland for a couple of years, which was, in some ways, for the best.

No one other than his mum. She had tried to get him off it on numerous occasions, but nothing had worked. She’d talked to every doctor and addiction counsellor she could find to see what she could do to help, but the answer had been clear: not much, at least until Roland wanted to be helped.

That time had come six weeks ago when Agnes, Roland’s girlfriend, had died of an overdose, after which Roland had turned up at their parents’ house and declared he wanted to get clean.

He had succeeded, to a point. There had been a few relapses – one occasion he had gone missing for two days, before arriving one morning on Tom’s parents’ doorstep, filthy, pale, thin and exhausted. Tom was there with Jo, and he had left in disgust. His parents were free to welcome Roland back, but Tom had no intention of doing the same. He was not planning on Jo being cradled in her uncle’s pipe-thin, needle-scarred arms.

The doorbell rang again. He laid Joanna in her Moses basket and went to let Martha in. She had short, tidy hair, and a lithe, muscular build, even in her sixties.

‘Good morning,’ she said. She came from Yorkshire, and had retained the fat vowels of her childhood accent, although there was also a hint of New Zealand in her voice. ‘How’s Jo? Did she sleep?’

‘Not much,’ Tom said. ‘About the same as usual.’

‘Oh well,’ Martha replied. ‘It’s tough, but it’ll pass. They all get there in the end.’

‘If you say so,’ Tom said. ‘I don’t dare hope.’

He followed her into the living room. A slow, warm smile spread over Martha’s face when she saw Jo. She bent over the basket and made a quiet kissing noise.

‘Well, she’s asleep now,’ she whispered. ‘She’s beautiful, Tom.’

‘I think so,’ he said. ‘But I’m biased.’

‘No. You’re right. She’s a darling.’ Martha put her bag on the couch. ‘Well,’ she said. ‘If it’s OK, I’ll make myself a cup of tea while she’s sleeping. Alice is back around noon, she said?’

‘Yes,’ Tom said. ‘There’s a press conference this morning.’

‘About the murders?’

‘Yep. She thinks the police are going to say there’s a serial killer.’

Martha looked genuinely shocked. ‘That’s terrible. The streets aren’t safe. You won’t find me out alone, especially at night.’

‘I don’t blame you.’

‘Anyway, you go off to work. I’ll be here until Alice gets home.’

‘Before I go,’ Tom said. ‘There is one thing I wanted to mention.’

‘What’s that?’ Martha said.

Tom faltered, momentarily. He was not looking forward to this conversation.