As she nears the ground floor, she gazes into the large hall where poor Alice Dunning was caught red-handed with powder, perfume and a few hairnets.

Alice will have settled into Holloway life by now. No one wants to be inside, but at least Alice will be glad to be far from her husband and his ever-swinging fists. Even while she’s surviving on prison food and shredding the skin of her fingers picking apart coir rope, she will count this time as a blessing.

Ruby pauses on the lowest step.

Harriet Littlemore, clasping her pink box to her chest, is walking towards her.

Harriet has found a new powder compact and discovered a push-up lipstick in a shade that is darker than her usual rose. Satisfied with her morning’s purchases, she makes her way to the main door, where the taxicab will be waiting for her. She might even head to the office before lunch.

Something causes her to turn and lift her eyes to the marble staircase.

The young woman descending the steps, with a sway to her hips, is unmistakably Ruby Mills.

Harriet stops dead and stares, her mouth forming a small ‘O’.

Ruby stares back. A sly smile spreads across her face. And then she continues walking towards Harriet, slowly, like a cat stalking prey, until they almost touch shoulders in the foyer of the store. She says nothing, only looks at Harriet as other women, and a few men, drift around them, oblivious, on their way to buy or browse.

Harriet’s heart beats harder inside her chest. The girl is smaller than she is. Up close, she is clearly underfed, and her skin is pale, but there is a ferocity about her, an energy, that is unnerving. Thrilling. Harriet swallows down her anxiety. She does, after all, hold the advantage.

‘Ruby Mills,’ she says, quietly but confidently.

The girl’s eyes widen at the sound of her name. Green eyes. Now she flicks her gaze up and down, almost nonchalant, dismissive, taking in Harriet’s whole appearance before looking directly at her face again.

‘Harriet Littlemore.’

Harriet cannot prevent the nervous gasp emerging from her throat. ‘How do you know my name?’

Ruby grins. The gaze is fearless. Defiant.

‘How do you know mine?’

‘I watched you escape Mr Enderby’s shop,’ Harriet says, hurriedly. The girl tilts her chin at this. ‘And I know that you lifted a very beautiful mink coat – along with other items – from Hartleys before then.’

Ruby’s eyes remain locked on Harriet’s. ‘I don’t much care for mink. Nor for Hartleys.’

‘No, diamonds are more your thing, aren’t they?’ Harriet stands her ground, but her breath is shortening.

There’s a flicker of amusement in Ruby’s face. ‘Now you’re talking. You don’t happen to have any on you, do you?’

Harriet clutches the box. Her left hand, ungloved, answers.