‘Can you open the door for me?’

The woman hesitated, then shut the door and Nell heard the scraping of metal on metal.

‘You’re here about the dead man?’ the woman asked.

‘Yes. We’d like help identifying this woman.’ Nell held up the picture. ‘Do you recall seeing her in the days leading up to his death?’

The woman examined the picture, then said, ‘I can’t see her.’

‘I know it’s a poor image, but if you could think back to see if you remember a woman with long brown hair, it would be really helpful.’

The woman slowly shook her head. ‘No. I mean, I haven’t seen her.’

Nell looked at the carpeted staircase ingrained with the dirt of years. ‘Is there anyone else who lives here?’

The woman instinctively pulled the door towards her a little. ‘Why?’

‘Because maybe they saw this person?’ Nell could see her trying to judge whether it was a trap.

‘My husband and child. But he’s at work and my son is too young,’ the woman replied.

Nell nodded and pulled out a card. ‘Can you ask your husband to get in touch if he remembers anything?’

The woman looked unsure but took the card.

‘Will you do that?’ Nell asked.

The woman read it, glanced up at Nell, then back down. ‘Yes.’

‘Thank you. Have a good day.’

The woman had shut the door before Nell had finished speaking.

Nell saw Paul was further along the road, so she was playing catch-up. Four more doors with no answer and she was matching him.

‘Any joy?’ she called over, knowing he would have said if there was.

‘Not yet,’ he called back.

‘OK, let’s keep going to the end, then we’ll try the backstreets.’

Nell knocked on two more doors, feeling the case slipping away from her as each time she was met with silence. Two doors left and she checked on Paul, deep in conversation with a male occupant. She felt relief that at least someone was home and was about to knock on the last-but-one door when she heard her name being called.

‘DS Jackson?’

Nell turned to see the woman she’d spoken to earlier hurrying towards her, the gold flecks in her ankle-length dress catching in the sun.

‘DS Jackson, I think I remember something.’ The woman came to a breathless halt on the pavement beside Nell.

‘I forgot before – I remember the woman with the brown hair.’

Nell suspected she hadn’t. Rather she’d gone back into her flat and her husband had agreed she could remember the woman.

‘I only saw her once, across from our flat,’ the woman continued. ‘She was standing under a street light so that’s how I noticed her.’

‘And when was this?’ Nell took out her notepad and started to write.