‘What’s happening?’ she muttered.

Porter no longer had any idea. When he first heard the explosions he reckoned it must be the Regiment coming in to rescue them, but now he wasn’t so sure. They might have used some stun grenades to prepare the way for an assault. Maybe some gas. But this looked like some kind of cruise missile making a direct hit on the mine. Why the hell would you do that? It would risk killing the very people you were meant to be capturing.

Her voice was cracked and weak, but as Porter cradled her in his arms, he could feel some of the strength coming back to her. For the first time in days she believed she might live, and it was amazing what resilience that knowledge could give a person.

‘Reckon we can get out of here?’ said Porter, glancing at Hassad.

He didn’t reply, but the brutal expression on his face suggested he didn’t think so. Porter pointed his gun straight at the man, nudging him forward, while holding on to Katie as well. He pulled the door ajar, reeling back as a cloud of thick black smoke hit him straight in the face. He coughed violently, his whole body shaking as his lungs tried to get rid of the air he’d just breathed. ‘Corpses,’ he whispered, his face drained of all colour.

Porter put Katie onto the ground, and held his breath as he slipped his face around the door, glancing out into the corridor beyond that ran down to the meeting point. It took a moment for his eyes to adjust to the clouds of smoke, and the fumes that were stinging his pupils, but as he focused it was clear that the mine had been turned into a scene of total devastation. The two fighters who normally stood guard against the door had been reduced to a couple of charred skeletons, and there were more corpses as you looked towards the meeting point. A huge fireball, Porter reckoned, must have swept down the corridor, burning everything it met, then, as it sucked all the oxygen out of the space, it would have extinguished itself, leaving behind the heavy clouds of smoke. Only the thick door to Katie’s cell had saved them. Even so, to get out they would have to fight their way through the smoke, and the secondary fires and explosions still rippling through the rest of the mine.

Porter tore the shirt from his back. ‘Tear this into three strips, then dunk them in water and put one over your mouth,’ he barked. ‘It’s the only chance we’ve got.’

‘You were pointing a gun at my chest five minutes ago,’ Hassad growled.

‘And you bloody deserved it,’ Porter snapped. ‘But unless we work together, none of us has a chance of getting out of here alive, so let’s just get free of this place, and then carry on our fight later if we have to.’

Throwing the AK-47 he had taken from Hassad across his back, Porter knelt down, and tied the strip of wet cloth across Katie’s face. It would help the keep the fumes out of her face. Then he slipped a strip around his own mouth, knotting it tightly around the back of his head. He hoisted Katie into his arms, and headed for the corridor. She was a good-sized woman, at least five eight, and when she was fit would probably have weighed considerably more than she did now. He could feel at once how frail and weak her body had become. Even a fit person would have trouble walking through these fumes, he thought bitterly.