In the Dry Season, Mitchell Falls is simply a series of five neat, tiered cascades. But following the Wet, as in this shot, the watercourse becomes a torrent. The individual steps are lost in the thunder of the whole, and the water takes on the blur of massive movement. At this time of year it is impossible to access the falls by land. I was dropped in by helicopter and took this photograph from a cliff-top, marvelling at the sheer power of the water below me. The rainbow in the foreground was an added blessing, like a touch from heaven. This was nature at its most primeval, a scene that seemed to evoke feelings from the very beginnings of time.