On the mud’s surface were dead fish that must have jumped out of the river to escape the heat. There was a lot of debris in the flow, from dust to pebbles to small boulders: no wonder it was so abrasive.

Even with the suit’s strength augmentation the mud was difficult stuff to wade through - lukewarm, and with a consistency like wet cement. The stench was bad enough for me to pull my visor over my mouth. By the time I reached the cottage I was already tiring badly.

I found the little ‘family’, parents and child, terrified, glad to see me. The woman was bigger, obviously stronger than the man. I had her hold her infant over her head, while I slung the man over my shoulder. With me leading, and the woman grabbing onto my belt, we waded back towards the higher ground.

All this time the mud rose relentlessly, filling up the valley as if it had been dammed, and every step sapped my energy.

Lian and Doel helped us out of the dirt. I threw myself to the ground, breathing hard. The young woman’s legs had been scoured by rocks in the flow; she had lost one sandal, and her trouser legs had been stripped away.

‘We’re already cut off from the bridge,’ Lian said softly.

I forced myself to my feet. I picked out a building - not the largest, not the highest, but a good compromise. It turned out to be the hospital. ‘That one. We’ll get them onto the roof. I’ll call for another pickup.’

‘Sir, but what if the mud keeps rising?’

‘Then we’ll think of something else,’ I snapped. ‘Let’s get on with it.’

She ran to help as Doel improvised a ladder from a trellis fence.

My first priority was to get Tilo safely lodged on the roof. Then I began to shepherd the locals up there. But we couldn’t reach all of them before the relentless rise of the mud left us all ankle-deep. People began to clamber up to whatever high ground they could find - verandas, piles of boxes, the ground transports, even rocks. Soon maybe a dozen were stranded, scattered on rooftop islands around a landscape turning grey and slick.

I waded in once more, heading towards two young women who crouched on the roof of a small building, like a storage hut. But before I got there the hut, undermined, suddenly collapsed, pitching the women into the flow. One of them bobbed up and was pushed against a stand of trees, where she got stuck, apparently unharmed. But the other tipped over and slipped out of sight. I reached the woman in the trees and pulled her out. The other was gone.

I hauled myself back onto the hospital roof for a break. All around us the mud flowed, a foul-smelling grey river, littered with bits of wood and rock.