‘You promised! We spoke to your people, now it’s my turn.’

‘Listen, dear, I have reason to believe there is an … unwelcome spirit in this house, and rather than calling things up, it would be better if we tried to send her back—’

But something has snapped within Pearl, she has none of her usual timidity. ‘When I’ve had my séance,’ she cries. ‘Or don’t you mean to keep any of the promises you made to me?’

This hits home. Agnes hangs her head. ‘I do regret that Dr Carfax was not able—’

‘He’s dead!’ – Pearl is almost shrieking – ‘You told me I’d be able to cure my father, and now he’s dead. Does that sound like you’ve kept up your end of the deal?’

‘No, but—’

‘So either you’re going to help me talk to him, or you’re a bloody liar. Which is it?’

Misgiving wallows within her. What choice does she have? The poor girl is sick and half-mad with grief. Agnes must humour her, keep her occupied until Simon arrives. From the way she is breathing, she is very ill indeed.

‘One séance,’ Agnes concedes. ‘Just one. And then we put the ghosts back, for good.’

Pearl sighs in relief. Then she throws up.

No candles burn this time. It is pitch-black, but Pearl is a faint, indefinite outline in the dark. She is propped up against pillows, determined to proceed no matter how eloquently Agnes entreats her not to.

The house still smells of vomit. If Agnes possessed better eyesight, she would have sworn that the liquid had glowed. She scents something acidic, corrosive, like the very reek of death.

‘Give me your hands,’ Pearl demands.

Agnes obeys. It is like holding a bunch of wet sticks. She closes her eyes and prays for Simon to arrive quickly.

The grandfather clock pings.

Her eyelids snap open. That clock has not made a sound in days. She waits for it to tick, but nothing happens; there is just a taut, expectant hush.

‘Father,’ Pearl whispers passionately. ‘Father, come to me. I’m so sorry. I tried my best.’

A single flame crackles into life in the fireplace.

Agnes attempts to tug her hands back, but Pearl clings to them like a drowning girl.

This is wrong, it is all wrong. The flame is a light, however small, and light creates a doorway for the shadows to come slithering out.

‘Father,’ Pearl pleads. ‘Don’t be angry.’

Agnes holds her breath. There is anger in the air, palpable but invisible; it seems to pulse and thicken. They should stop, they really should stop.

‘Talk to me!’ Pearl cries.

The hands of the grandfather clock start to move; faster than any mechanism could push them. The pendulum begins to swing.

‘Pearl—’

Sweat stands out on her ivory forehead. The girl is straining with all her might.

Agnes watches, helpless, as the fire climbs in the grate.