Perry introduced himself and showed his detective ID card.

‘Did I just park my Rolls-Royce in the wrong place?’ She guffawed at her own joke.

‘No, Mrs Garrison. It’s about something—’

‘Ah, yes. Still digging for my granddaughter after all these years, then?’ she said softly, her face tightening.

Perry explained slowly and carefully about the recovery of Jane’s body. ‘We believe she has been kept frozen for nearly forty years.’

‘I heard about it. I expect you think that my son Harold did it, don’t you? Him having a fish freezer and all.’

‘We are keeping an open mind.’

‘Are you now?’ she asked with a slight smile. ‘That would be a first for the filth.’

Perry thought carefully about how to approach this prickly woman, his last remaining potential witness. If she didn’t cooperate, he’d be stuck. ‘Before I get to all that, Mrs Garrison, can I ask you about your grandson, Graeme?’

She began to cough violently, bringing up something liquid into a handkerchief that she apparently kept for the purpose by her bedside. ‘I’ve not seen that one for a long time.’

‘Since when?’

‘He came crawling round asking for money more than ten years ago. He knew that we’d finally sold the Balham properties, that was my house and the shop in Hildreth Street, for a tidy sum, so I could come and live here. He just assumed there would be lots spare. Just like his bloody father.’

‘That would be Harold.’

‘Yes, my Harold, God rest his twisted soul.’

‘Tell me about Graeme’s childhood. I presume you enjoyed playing with him in the early years?’

She narrowed her eyes and pursed her lips. ‘He was a difficult baby, always crying as I recall. By the time he was seven or eight, he was quite big and he used to bully the girls out in the street. Hair pulling, pinching, stuff like that. My Harold tried to thrash it out of him, but it was no good. What comes from bad always turns bad doesn’t it?’

‘Why do you say Graeme comes from bad?’

The old woman licked her lips, but said nothing.

Perry saw his opportunity: ‘Graeme wasn’t Linda’s child, was he? He was Jane’s.’

A shadow passed over her face, an ancient agony which distended her mouth. With a supreme effort she organised her features into the matriarchal antagonism that had presumably served her well for decades. ‘Well, well, the good old British bobby gets there in the end. Even if it takes nearly half a century.’ She felt for a fresh tissue, and dabbed the corner of her eyes.

‘Care to tell me about it?’ Perry said.

She sighed deeply, clicked off the TV, and then continued. ‘Look. I’ve seen everyone I ever cared about die, you know. First was Linda, then Frank, my Harold and finally Eileen. She hung on until the end, hoping to find out what happened to her daughter before she died. But in my heart I always knew. It was a truth too terrible to tell.’