I think Hacket and I moved forward at the same moment. We came together in the doorway and stopped there, holding our arms up to shield us from the heat and staring in blank hopelessness. There was no passage any longer, no refectory room — no courtyard, no main archway. There was nothing there but a pile of broken stone and beyond it the lava heaped twenty, maybe thirty feet above us.

‘The abbot’s room,’ Max shouted suddenly. ‘There’s a window there.’

We scrambled back to the robing room in a body, choking the doorway. The window was high up, narrow, and of stained glass, leaded and barred. Hacket seized hold of a crozier. I saw Zina’s mouth open in horror at the sacrilege. But it was just the thing we wanted and Hacket was essentially a practical man. Max and I dragged chairs in from the chapel and piled them up while the American smashed the glass in. The lead was thin and bent easily. He smashed at the crossbar. The iron gave and broke under his blows. ‘Up you go, Countess. And you, Miss Tucek.’

They scrambled up. ‘Feet first,’ Max called. Zina was halfway through when she looked down. Then she cried out something and clung frantically to the stone frame of the window. ‘Jump!’ Hacket shouted at her.

‘I can’t,’ she screamed. ‘It’s a long—’ Her voice died in a fluttering scream as Hilda, who had seen more of the lava and realised the urgency, pushed her through. Tucek and Lemlin we got up that crazy scaffolding of chairs somehow. They seemed weak and in pain. Hacket went up with them and helped them through. ‘They’re drugged,’ Max explained. ‘And the bloody swine had them chained.’

‘Chained to the wall?’ I asked.

He nodded. ‘Imprisoned in the fetters they used for heretics. Fortunately they were rusty and we were able to smash some of the links. You go on, Hacket,’ he called. ‘Now you, Dick.’ I hesitated. ‘Go on, man. I’ll give you a hand up, if it’s your leg that’s worrying you.’

I scrambled up, caught hold of the stone of the window and slid my legs through. Max was right behind me. It happened as I clung there, steadying myself for the drop, getting my tin leg under me. There was a crumbling roar. I caught a glimpse of the roof cracking and falling and then I let go. I fell on my good leg and rolled sideways, conscious of a horrible jar on the stump of my left leg and hearing a thin scream that for a second I thought was myself screaming with pain.

But it wasn’t I who had screamed. It was Maxwell. He had his head half out of the window and his face was contorted to a frightening mask of pain. Above the window rose the dust cloud I’d seen so often in the past few hours. We were looking at a wall with nothing behind it. I shouted up to Maxwell. He didn’t say anything. Blood was running down his chin where he was biting through his lower lip as he heaved at the rest of his body. ‘It’s got my legs,’ he hissed down.

‘Try and pull’em clear,’ Hacket shouted. ‘We’ll catch you.’ He signalled to me to join him under the window. ‘Easy does it, fellow. Come on now. Get out of that and we’ll soon have you safely tucked up and comfortable.’