The biggest drawback to tracing a missing person from the official point of view was that there was nothing illegal about disappearing. Unless there was a suspicion of foul play, the police could do nothing, which produced the ironical situation that the greatest experts in the field were the Salvation Army, who handled something like ten thousand British and foreign enquiries a year from their Headquarters in Bishopsgate, London, and who were constantly in touch with centres throughout the country such as the Stone Street Citadel.

The young man emerged from the inner office, his arm around the shoulders of a middle-aged woman in a shabby coat who had obviously been weeping. He nodded briefly without speaking and Miller brushed past them and went in.

Major Martha Broadribb was exactly five feet tall, her trim uniformed figure bristling with a vitality that belied her sixty years. Her blue eyes were enormous behind steel-rimmed spectacles and she had the smooth, unused face of an innocent child. And yet this was a woman who had laboured for most of her life in a China Mission, who had spent three terrible years in solitary confinement in a Communist prison camp.

She came forward quickly, a smile of genuine affection on her face. ‘Nicholas, this is nice. Will you have a cup of tea?’

‘I wouldn’t say no,’ Miller said. ‘Who was that who just left?’

‘Poor soul. Her husband died a year ago.’ She took a clean cup and saucer from a cupboard and moved to the tea-tray that stood on her desk. ‘She married one of her lodgers last month. He persuaded her to sell the house and give him the money she received to buy a business.’

‘Don’t tell me, let me guess,’ Miller said. ‘He’s cleared off?’

‘That’s about the size of it.’

‘She’s been to the police?’

‘Who told her that as he hadn’t committed a criminal offence they were powerless to act.’ She stirred his tea briskly. ‘Four lumps and much good may it do you.’

‘Do you think you’ll find him?’

‘Certain to,’ she said, ‘and he’ll face up to his responsibilities and do right by the poor woman after I’ve had a chance of talking to him. I’m certain of that.’

Another one who thought most people were good at heart. Miller smiled wryly, remembering their first meeting. On his way home one night he had answered an emergency call simply because he happened to be in the vicinity and had arrived at a slum house near the river in time to find a graceless, mindless lout doing his level best to beat his wife to death after knocking Martha Broadribb senseless for trying to stop him, breaking her right arm in the process. And the very next day she had visited him in the Bridewell, plaster-cast and all.

She lit a cigarette, her one vice, and leaned back in her chair. ‘You look tired, Nicholas.’