‘That bastard Nard has betrayed us!’ Ven says, grabbing his backpack. ‘Come on, there’s a walkway to the next building on the fifteenth floor.’

Footsteps are thundering up the stairs. It has to be guards. I snatch a revolver from my bag and press it into Kay’s hands. We rush after Ven, who is taking the stairs two at a time. I hear a hissed command below us. I can’t believe we were worrying about a bomb and all this time Nard just wanted to use Kay to show the guards where to catch us in the act. Does he really hate me that much? Enough to ruin our chances of taking down The Leader?

We keep running. Looking over the bars, I see a flash of red beneath us. It’s guards all right. Ven and Kay are already ahead of me. I work my aching legs faster. We reach the next landing. My gun is heavy in my hands. What is Ven’s plan? What can we do, even if we make it into the next building? I’m too breathless to ask him. The footsteps are louder and closer. I think about angles of sight. Once they reach the floor below us, will they be able to get a clear shot?

‘Keep,’ I gasp, ‘to . . . the wall.’

Ven and Kay obediently move towards the wall as they run on. I’m falling behind again.

I look up. We’re still a long way from the fifteenth floor. I stumble on and risk a look back. The guards are definitely gaining on us. Outside, I can hear children singing.

‘Ven,’ I say, ‘we . . . won’t . . . make it.’ We’ve reached a landing and I stop. It’s better that we hide, so we’ve got the advantage when the shooting starts. Ven and Kay stop too. Ven looks back, and then up. He freezes. It’s his first moment of indecision I’ve seen since we met. I move behind a pillar and try to pull Kay with me, but she steps in front of Ven, her back to his front, and flings his arm around her neck. The guards round the corner. They see a tiny blonde Girl Guard apparently taken hostage by a member of the Resistance.

‘Help me!’ Kay screams. ‘They’ve got me!’

The bunch of guards look at each other in confusion. I put a bullet through the forehead of the nearest one. Ven and Kay send a spray of fire across the front row before they’ve even realised what’s happening. They tumble backwards, knocking over those behind.

‘This way,’ I say, flinging open the door behind me and running into another open-plan office space. Outside, music is pumping. I dive behind a desk then twist on to my knees and raise my gun. A guard pushes through the door and I shoot him right in the chest. He falls. Another guard – Ven hits him first. Then a jumble of them push through the door together and we’re all shooting at the same time. Redclad bodies hit the floor again and again. We’re killing them. Efwurding hell, I’m shooting guards and I’m killing them. Out of the jerking mass of red, one of the guards breaks free and runs towards me. I fumble and my gun slips as he lifts his and aims. He’s only a few metres from me and as I duck I know that his bullet is heading straight for me. It whizzes past my cheek. The guard stops like he has hit an invisible wall and then crumples.

Kay has shot him in the neck.

I turn my gun back to the door, but there is no need. No more guards come.

Outside, the rousing music thumps and jingles on. Has no one heard all the shooting?

My heart is banging against my ribs. ‘Kay? Are you all right?’

Kay stands up from behind a knocked-over table and gives me a shaky smile.

‘Yes, thank you, Blake,’ Ven says, from his corner of the office. ‘So kind of you to enquire. I am entirely unhurt. Don’t tax your limited emotional intelligence by worrying about me further.’

My hands are shaking. I put down my gun and press my palms to my face. I can’t believe what just happened.

‘I dropped my bag,’ Ven says. ‘Give me some ammo, Blake. Kay, check they’re all gone.’

I toss my bag over to Ven. Kay moves to the door, stepping over the bodies. There must be a twenty of them. She pulls the door open a crack.

‘I th— Ah!’

The guard lying nearest to Kay has grabbed her by the ankle. She swings her gun around, but he knocks it flying out of her hand. Kay twists and shakes, but the guard scrambles on to his knees and grips her arm.

‘Get off!’ Kay shouts.

I run towards them. The guard lets go of Kay for a second to pull a revolver from his waistband. Kay sees him. She spins round, flicking out a leg to kick the gun from his hand, but he pulls back and she misses. The guard snatches at the back of her jacket and, as she continues to turn, it rips right across the back. Something falls out of the lining and on to the ground.

‘STOP!’ yells Ven.

Everyone freezes.

Ven is still in his corner, holding my bag.

The guard clutches his gun centimetres from Kay’s stomach.

I am near enough to reach out and touch him.

And we’re all staring at the flashing red light on the bomb that has just tumbled out of Kay’s jacket.