My gaze fell to the page, reading exactly what they had said. I could almost hear their frightened voices.

On the fourth day she faltered in speech, and presently afterwards expired. The other girls, seeing the whole weight of her body supported by the strings which confined her to the door, were greatly alarmed, and called out: ‘Miss Sally! Miss Sally! Nanny does not move.’ The daughter then came upstairs, saying: ‘If she does not move, I will make her move’; and then beat the deceased on the head with the heel of a shoe.

‘The Metyards tried to revive Anne,’ Eliza said, ‘but she was dead. She was thirteen.’

I should have been shaken, but I had heard too many stories like this over the past few months. Part of my education had been learning about the more famous spirits of the capital.

‘Of course, they tried to conceal Anne’s death,’ Eliza continued. ‘They claimed she’d run away and hid the body in a box in the attic for two months, but they couldn’t mask the smell of it for ever. Sarah Metyard removed and burned the hand with the missing finger, in case it could identify Anne, but decided not to risk burning the rest in case the neighbours got suspicious. Eventually, they cut up the body, and Metyard disposed of the pieces in a public sewer – a gully-hole, as they called it at the time.’

‘Some versions of the story say that they killed Anne’s eight-year-old sister Mary, who was also one of their apprentices,’ Nick said. ‘A watchman discovered the pieces of Anne’s corpse, but it was assumed that they had been dumped there by a body-snatcher or a surgeon, so nobody investigated.’

‘It seemed like they’d got away with it,’ Eliza said – she was clearly enjoying her role as a storyteller, ‘but as the years passed, Sarah grew more abusive towards her daughter. Sally finally went to live with a man named Richard Rooker, who had offered her employment. She moved away with him and became his lover, but Sarah wouldn’t leave them alone – she was obviously worried that Sally would tell someone about the murder. Eventually, Rooker overheard a confrontation between them, had a bad feeling about what he’d heard, and questioned Sally, who admitted everything. Rooker alerted the authorities, probably thinking Sally would get a lighter sentence, as her mother had done so much to influence her behaviour – but she didn’t. Both Metyards were hanged at Tyburn—’

‘—in 1768.’ Nick snapped the file shut. ‘The spirits of murderers often seek out those of their victims. I’ll wager that Sarah Metyard, now she’s been set off, is after Anne Naylor.’

I wet my lips. And only a few months ago, I thought that the dead stayed dead.

‘So,’ I said, trying to sound as if I found this all perfectly normal, ‘do you know where Anne is?’