‘The other thing we know is that Margaret was given to good causes,’ she continued. ‘All sorts of good causes, but especially a charity called the Haven.’

‘That place for fallen women in Holypool Village.’ Charlie looked up from his mug of coffee.

‘Fallen women?’ It was Holly, her voice a horrified shriek. ‘What century are you living in?’

‘I was being ironic.’ Charlie slid her a grin.

Vera thought that something had definitely happened in his life. He’d never have talked about irony before. ‘How do you know about the Haven?’

‘I arrested a young druggie once. No room in the cells, and I didn’t think she was fit to let out onto the street. Seemed to me she might be suicidal. Social services suggested I took her there.’

‘Joe, will you check out the Haven? You’re good at social work, when you put your mind to it. If Margaret was a regular volunteer she might have made friends with the staff, confided in them about family, relationships. And it’s possible she made an enemy of one of the women. Gruskin said they were vulnerable. Anyone with a history of mental illness, given to paranoia and violent episodes? Or an ex-offender with some sort of axe to grind.’

Joe nodded and scribbled down the address.

Holly lifted her hand. ‘If there are victims of domestic violence there, Margaret could have been targeted by a male partner.’

‘So she could, Hol.’ Vera was pleased that at least now there were lines of enquiry, but she still thought the centre of the investigation lay in Harbour Street. She leaned back against the desk and shut her eyes against the sun. ‘And the owner of the guest house, Kate Dewar – formerly known as musician Katie Guthrie – has a new man in her life. Stuart Booth. No record, not even a speeding ticket, but let’s see what we can find out about him. Track down any former partners. Any history of violence? And we’ll need to chat to the head of the school where he teaches.

‘The rest of you: we’ve set up interviews with the folk who were on the train and who’ve already been in touch. Treat them nicely, but be aware that any one of them could be the killer. So no dismissing the smart guy in the suit because he doesn’t seem the type. We need to know where they were sitting or standing, and if they saw anything unusual. Margaret’s hard to pin down socially and she could have mixed with all sorts. We’re especially interested in the people who got on at Gosforth. Did any of them see Margaret on the platform, or notice which direction she walked from to get there?’

Charlie coughed. ‘Ma’am?’

‘Yes?’ She lifted an eyebrow.

‘Don’t the Metros have CCTV these days?’