Kat pushes away from the window and launches herself out of Beth’s gate. She looks left and right, then runs over to a yellow skip at the side of the road – piled high with rubble from yet another extension – and grabs the biggest piece of concrete she can carry. Holding it in two hands, she races back to Beth’s house, and without thinking twice, hurls it through Beth’s living room window.

There’s the high-pitched screech of shattering glass and then a deep thud as the concrete slab hits Beth’s living room floor. Kat surges forward. She needs to get to Saskia. With the thick sleeves of her parka pulled over her fists, she frantically pushes the loose fragments of glass out the window frame, then heaves herself through the hole. She can hear the snagging of material, and feel the sting of cuts where her skin is exposed, but neither slow her down.

Saskia is slouched on the sofa, her hands at her throat, swollen lips open as she searches for breath, the creaking drone of her wheezing filling the room. Kat knows she’s in anaphylactic shock, and that she could be dead in minutes. Beth isn’t moving at all. She looks like a young deer caught in a car’s headlights. Beautiful, startled, innocent. But Kat knows the truth.

‘She needs an EpiPen!’ Kat screams. ‘Does she carry one?’ Kat’s eyes spin around the room. ‘Where’s her bag?!’

‘I don’t know what’s happening to her,’ Beth finally says, her voice trembling. Even now, she’s playing the role perfectly; only her hands give her away, the sound of nails scratching skin.

‘You poisoned her – that’s what’s happening,’ Kat spits out. She spots Saskia’s coat on the sofa beside her and starts rummaging through the pockets. Nothing in the deep outside ones, but she sees the slim ridge of something inside the breast pocket.

‘No, I didn’t,’ Beth counters. ‘I didn’t know she had an allergy.’

‘Bullshit!’ Kat exhales loudly. She reaches inside and yes, it’s an EpiPen. ‘Even I know she’s allergic to nuts; it’s all over her social media. She volunteers for an allergy charity, for fuck’s sake!’ Living on a farm five hours from the nearest medical centre means that Kat has had first-aid training, including how to administer epinephrine. She flips off the blue cap, takes a second to line it up with Saskia’s thigh, then jabs the orange tip in at a right angle.

‘No, sorry, I didn’t mean that,’ Beth stutters. She takes a step backwards, unsteady on her feet. ‘I mean, I didn’t know there were nuts in those mince pies. That’s it. Simon’s mum sent them to us, you see. I didn’t think for a moment that—’