I spun around to the bank, trying to clutch at handholds, knowing I didn’t have time to pull myself up. But Tipene seized my shoulder, yelled into my ear. He was trying to go first?

No. ‘The ledge!’ he shouted. ‘Get onto the ledge!’

Next second, we were sloshing and scrambling onto the rocky lip where the carving had lain, squashing ourselves into the narrow cleft behind it. Stones scraped against my sides. I hunched my back, forcing myself further in, clutching at rocks jutting from the walls.

A monstrous booming filled the world. The light changed as a great sheet of muddy foam lifted above us. We braced our legs and hips against the sides. I screwed my eyes shut.

The wave slammed across the shelf where we’d been standing, and the solid stone trembled. Then we were underwater as it gushed into the gap where we huddled, shoving and ripping like some wild animal, ramming us against the walls. Sharp rock tore at my cheek.

Tipene lost his grip. I felt the river pluck at him; one arm slipped, and his body twisted sideways, out into the raging current. I snatched at him, so hard that my fingers sank into the flesh of his shoulder. He reeled back against the rocky wall of the crack; his head whacked into it. I held on, back jammed against the stony wall, hands locked onto my friend. We were still underwater. My lungs ached; the current yanked at me. Tipene sagged limply.

I had to breathe. I must. And right then, the water surged away as fast as it had covered us, and I crouched, dripping and gasping, half out of the gap. Tipene lolled in my grasp, slumping into the water that now churned around our knees.

I gulped, choked, managed to yell. ‘Hold on!’ My friend didn’t move. ‘Tipene!’ I saw blood sheeting down his face from the matted hair, remembered that impact of his head against the stone.

My teeth ground together in a snarl. I set my legs against the wall and heaved. Tipene half-slithered, half-slumped up into the gap beside me. Something hard scraped my ribs: the carving inside his shirt.

My heart thudded; my breath rasped. ‘Tipene! I bawled again. ‘Help!’ No movement. Blood poured down his cheek.

The river charged past. Just four steps away from where we hunched, it was still a thundering torrent, but around us it had dropped to shin-height once more. The wave from the burst dam or whatever it was had passed. But I couldn’t get up the bank; if I let go of my friend, he’d collapse onto the ledge, be swept off it into the current. We were trapped.

I shook him. ‘Tipene!’ He hung in my grip, a dead weight.