Whoever the second guard had gone to fetch was firing high and wild into the container, emboldened by the doctor’s decision to start shooting. Out of sight, hidden behind the halogen glare and the lip of the steel door, only his gun arm was visible – firing pistol rounds into the roof and walls around me. I stuffed the Grach into my jeans and hit the deck again. I rolled the dead guard over. Working fast, I unhooked his carbine’s tactical sling, and freed the assault rifle. The fire selector was set to single. There was probably a round in the chamber – but I wasn’t taking any chances. I snapped back the charging lever with my left hand as I brought the muzzle up. An unspent round spun out to my right.

Ready to go.

As the butt went into my shoulder and my cheek made contact with the stock, I fired. Out of the doorway the bullet ripped the guard’s hand off at the wrist. Arterial blood arced out across the opening. Another one gone.

I turned to the doctor on the floor, rifle still in my shoulder. He was sitting on the floor, face smeared with blood.

‘No, don’t!’ he said, the look of disbelief on his face morphing into a horror-mask of understanding, red hands held out in supplication. ‘Please. I’m just … I tried to save you …’ My shot-blasted eardrums distorted his voice like an over-modulating microphone. He sounded more machine than man.

‘Where am I?’

‘Please. I tried to save you.’

‘Save me? You tried to shoot me!’

I took a step towards him, and fired a shot close enough to his ear to nick it and draw blood. The round bounced off the floor and hit the rear wall with a spark. He screamed a deep, guttural yell.

‘Who are you?’ I shouted at him. I glanced at the dead guard. ‘Who are they?’

His right hand moved from his ear to his bleeding temple and back again. Tears welled in his eyes, snot bubbled under his nose. I settled the front sight post between his eyes.

‘Please! Please don’t. The guard. I tried to shoot the guard. Not you. Please …’

But he was right: he had saved me, or at least had allowed me to save myself. And the last thing I needed was another dead doctor on my conscience. The microsecond it takes to pull the trigger is the same hair’s breadth of time you have to decide not to. Instead of drilling a neat hole just below where his eyebrows joined, the little steel-core bullet stayed in the breech. He was breathing hard, covering his bloody face with his bloody hands.