One shot, she thought. One person dead, possibly. Why only one? Had Catherine Brown killed Pete in front of Meredith, part of her extended revenge plan?

Oh God, she thought, stop speculating and just get there. Emad was ahead of her, fleeter of foot and more agile. He’d been like that at school too, she recalled, a flash of a sports day memory coming to her. Sweet, doe-eyed Emad.

For the first time it occurred to her that they too were in serious danger, running full pelt through dark trees towards an insane person with a gun, their only weapon the handcuffs that she’d clipped to the belt loops of her trousers earlier. Two insane people, most likely, as Brown must have an accomplice. She didn’t escape until the morning after Pete went missing, so someone else must have taken him. And she’d had a getaway driver.

If anything happened to Emad, she would feel responsible. He was a rookie; this was his first life-and-death shout – and he wasn’t even on duty.

‘There’s the chopper,’ Emad panted over his shoulder. ‘Looks like they’ve found them with thermal imaging.’

‘Straight ahead then.’ Gemma felt like she’d gone into a sort of trance, her whole being focussed on getting there, like the time she ran a half marathon; one foot in front of the other, keep deep breathing … ‘Nearly there.’

What the hell do we do when we actually get there? she thought.

Even though she’d seen their clothes lying by the empty swimming pool, it was still a shock to see the twins stark naked, lying under a tree like two overgrown fairy-tale characters abandoned in the woods. Hansel and Gretel, Gemma thought. They’d been siblings too. There was something so primal about the sight – and that was before Emad’s torch beam landed on the bloodied body of who Gemma assumed was Catherine Brown and a bulky man lying motionless next to her a few feet away, like two harpooned whales.

‘Jesus,’ Emad yelped.

Catherine Brown had a number of visible stab wounds all over her face and torso, and an odd little curved blade sticking out of her neck, whereas the man was completely covered in blood from what looked like a shot to the chest. That must have been the shot they’d heard.

‘Meredith!’ Gemma called, running over to her, peeling off her stripy cotton jumper and laying it over the middle of Meredith’s pale torso.

Emad wished he hadn’t left his leather jacket in Gemma’s car – he was only wearing a shirt, but he stripped that off too.

Meredith was still clutching the pistol, her whole body shaking so much with cold and shock that Emad worried she might accidentally pull the trigger again.