Charlie meanwhile is shouting, ‘Fire!’ as loudly as he can, running towards Leadenhall to raise the alarm, Sarah, who he dispatches to do the same, pelting off in the opposite direction.

By the time the first Merryweather fire engine arrives, horses’ hooves clattering along the street, the fire, an everhungry beast, has already moved up to the first floor. Annie’s sketches, her paints, her paper – all are consumed in the blaze along with everything that remained in the basement: the skeleton of the Angel of the Thames, all of Edward’s jars, bones, specimens and medical notes, the mattresses in the cells, the blankets his angels once wrapped themselves in – all are now turned to smouldering ash.

It is only twenty feet or so but to Mary it feels like miles. As Etta holds the dog back by its collar, Mary runs towards the basement door, bile rising in her throat as fear almost overwhelms her.

Richard.

Please.

Please let him be safe.

I cannot—

Please.

The heat pushes her back like a wall of resistance then he bursts out, coughing, stumbling. Face black with soot, eyes streaming from the smoke, Annie in his arms like a dead weight, eyes closed and overcome by it all.

Richard falls to his knees in the yard, the cold flagstones sending a welcome chill through him as Annie rolls out of his arms and onto the ground, senseless but safe.

‘You bloody idiot!’ sobs Mary. ‘You bloody idiot, Richard!’

‘Sorry,’ he mutters, looking up at her as she throws herself at him, pummels him with her fists for a moment before holding him as tightly as she can, as she has wanted to for so long now. She digs her fingers deep into his hair, feels his warmth wrap around her as his arms clasp her tightly in return and she sobs into his chest.

Etta watches, sighs, breathes in London air. Ash and soot.

She turns to Natalya. ‘I, for one, have had enough of cities,’ she says softly, as she looks again at the fire, tendrils of flame now reaching through the roof. ‘Perhaps it is time we were going.’

‘Where?’ Natalya asks. ‘And how?’

But Etta only smiles at her as she steps forward, brings her close.

‘Put your feet on mine,’ she says. ‘Hold your arms around me. As tight as you can,’ and Natalya does so, wrapping herself around Etta and her white silk dress.

Etta looks up at the sky, takes a deep breath, and stretches her wings. She opens them out, lets them softly beat for the first time.

She looks back at Natalya and their eyes lock. ‘I have no idea if this will work,’ Etta whispers and they both smile.

Charlie and Jos burst through the back gate just in time as Richard motions to his beloved Mary.

‘Look,’ he coughs. ‘Look!’ And she turns her head.