‘We can go through to the living room,’ she said, gesturing through a doorway set in the wall to their left. She led the way and they followed close behind. The room was like something from a show home. Porter wondered if the sofas had ever been sat on. The cream leather looked smooth, buttery and unblemished, free from any telltale creases or wrinkles. A pair of matching two-seaters faced each other over a glass coffee table, with a single armchair from the same range at the head of the table. Mary Locke shepherded them towards the nearest sofa and took up residence on the other, keeping a safe distance, with the no man’s land of the coffee table between them.

Porter perched on the edge of the seat, loath to lean back lest he disturb the artfully arranged cushions that looked plumper than a Christmas turkey. Styles had no such qualms, settling back into a large mocha-coloured cushion and crossing his legs as he took out a small black notepad from his jacket. Mary Locke sat upright in the centre of her sofa, back straight and hands clasped in front of her on her knees.

‘I’d offer you a drink, Detectives, but I was just on my way out so can’t talk for too long. What’s this about, please?’

‘I’ll not waste any time, then,’ said Porter, with a polite smile. ‘We’re trying to locate your stepdaughter, Natasha. There appears to have been an incident at her flat and we’d like to speak to her about it. We’re hoping you can help us reach her.’

Porter studied her face as she absorbed his words. Her already stiff posture held firm; her tongue stole out a fraction and nervously wet her lower lip.

‘An incident? What kind of incident?’

‘A possible break-in and some kind of altercation is as much as we can say right now, Mrs Locke, but we really do need to speak to Natasha. Do you know where we can find her?’

She fidgeted slightly, smoothing away an imaginary crease on her trouser leg before clasping her hands back together.

‘I’ve … not seen Natasha for a long time, I’m afraid, not since …’ Her voice tailed off.

‘Not since when, Mrs Locke?’ prompted Porter.

She looked down at the floor for a second before she met his gaze again.

‘Not since just before her father died.’

‘So that would be April 1983?’ asked Styles.

She nodded slowly. ‘Nathan died less than a week after Tash’s birthday.’ Her voice tailed off as she spoke, her thoughts clearly drifting back to a memory she would rather not revisit.

‘And you saw her when, exactly?’ Porter asked.

‘Sorry,’ she said, aware she had been starting to drift. ‘Um, let me see. I think it was the day before her twenty-first birthday. I’d gone around to drop off her birthday card.’