Pom Pom is a small camp on an island in the western Okavango, six tents on raised decks looking out over a lagoon, reached by light aircraft from Maun because there is no other way. In late June the flood has arrived from Angola, the nights are cold and cloudless, and the dark is the real dark: no road, no village, no glow on any horizon. The soundtrack is hippo.

At about ten o’clock on the night of 25 June 2016 a guest stood on the deck outside their tent, looking up, because that is what one does at Pom Pom after dinner. They noticed a star that was moving, right to left across the sky, white, and pulsing every three seconds or so. They assumed a satellite and then stopped assuming, because it began to descend, and then it dropped, abruptly, straight down towards the water, and was gone.

Four or five seconds later a light came on above the tree line directly in front of the tent. The witness could not see the trees, but knew where they were. The light was very bright, white, and it pulsed with the same rhythm, and between pulses there was nothing there at all: no shape, no glow, no outline. It did not move. It sat above the trees and blinked.

That was when the witness noticed the quiet. The hippos had stopped. So had the baboons and the vervets that usually rattle the camp at that hour. The account, in all three versions the witness later filed, comes back to this: dead silence, in a place that is never silent, with the light pulsing over the water.

They watched for eight minutes or so, and then something that reads, in the telling, as stranger than the light itself: they went to bed. The camera was on the bed inside the tent, a few steps away. They did not fetch it. They wrote afterwards that they had felt dopey, uncomfortable, unable to think straight, and that it was entirely unlike them not to film something. Lying in the tent, they could still see the pulse through the mesh of the front flap. In the morning they asked themselves what on earth had happened, and then, over the next two months, asked MUFON, NUFORC and a third database the same question, submitting a photograph of the view from the deck with a note that the light had been above the trees dead centre.

Some things the report does not settle. There were five other tents in the camp and the account mentions nobody else on a deck. A single pulsing white light that descends and then holds station over water is the signature of a helicopter with a strobe, but there are no night flights in the Delta and nothing to fly for. A bright planet setting behind trees will flicker, and can seem to hang, but does not first fall out of the sky. The witness said they were not given to flights of fancy and wanted to know what they had seen.

The animals, presumably, started up again at some point. The witness was asleep by then.