‘I’ll do that,’ he calls over from his seat, without moving.

Ignoring him, she stacks the crockery in a neat row.

‘Are you out tonight or in?’

‘Jesus, Tom …’

‘I know, I know, I’m messing with you! I hadn’t forgotten. It’s on the calendar, right there, where it always is. So you’ll be back on Thursday?’

‘That’s right.’ She swallows, keeping her eyes trained on the dirty cutlery she is placing in the stand.

‘You’re going away again?’ It is Callum’s voice this time, and her heart strains so that it feels like it might tear.

‘Oi, what’s so bad about hanging out with your old dad? Come on, love, Mum’s got to work, you know that.’

It’s always Tom’s instinct to dive in to protect her from the decisions she has made, and his refusal to let her defend herself grates on her.

‘I’ll make it up to you,’ she says, the lie lingering in her throat. ‘I promise.’

As she opens the front door, she watches Sadie disappear around the corner of their street. Part of her wants to run after her daughter, to throw her to the ground and to hold them both there – to stop time, her face buried in Sadie’s neck, and somehow to go back and unravel the knot. Not back, she scolds herself as she loses sight of her daughter, for the last time on this street. How could she think that?

The walk to Tufnell Park tube station helps clear her head, gently easing her mindset from the domestic world to her other life. The trees lining Dartmouth Park Hill radiate new energy, their shoots a reminder that whatever happens, the world will go on.

Preparing to cross at the traffic lights, she starts to think through everything she has to do, and only now does it strike her that she has failed to buy credit ahead of time for the second SIM card she keeps tucked in the lining of her handbag. She swears under her breath as the green man fades to red, cursing herself for allowing such a pivotal element to fall through the net. But it’s pointless berating herself for it now – it is not an option, at this stage, to let things fall apart.

Heading into the newsagent’s diagonally opposite the station, she skims the headlines of the newspapers to distract herself from the fear that pummels at her stomach as she makes her way through the aisles, making sure there is no one here she recognises, no one to pull her up on why she is using a burner, probing her with their hilarious quips about her being not a civil servant after all but a spy, or maybe a drug dealer.

It was the kind of joke Tom had made when she was seconded to Russia, her first posting after joining the FCO. And her last.