La Rochelle sits in the Imbeza Valley north of Mutare, where the road climbs towards Penhalonga and the hills close in. Sir Stephen and Lady Virginia Courtauld settled there in 1951 and had the house finished by 1953, with an arboretum, orchid houses and a three-storey observation tower, and left it to the National Trust. By August 1981 it was, in Cynthia Hind’s description, a Forestry Commission station with a labour compound and a game warden, and the orchids belonged to a previous life.

Saturday 15 August was dull and overcast, and at six in the evening twenty workers came in from the fields with the light going. Their foreman, Clifford Muchena, told Hind what they saw. A ball of fire, a metre or a metre and a half across depending on which write-up you read, was rolling across the lawns. It took the slope towards the house and kept going. “It walked up the wall of the tower”, he said, went in at the top window and burst into flame.

Muchena ran to the warning bell by the house and rang for a warden. As he rang, the fire drew back into a ball, came down the tower wall past him and flared again at the Fantasy, the outbuilding that had once housed the orchids. He ran to put it out and found three men outside with their backs to him, watching the flames. He took one for his supervisor, the game warden Andrew Connolley, and called his name twice. The three turned round, slowly. “I couldn’t see their faces because there was so much light shining from them,” he said. They wore shiny overalls. Something in the light put him on his knees and held him there. When it went out, in Hind’s 1988 write-up, the fireball and the men were gone. In her 1989 retelling he crawled away and looked back at a black, empty night.

“All the time I was very frightened,” he said. The women in the compound, who had seen the fire too, had run into the bush with their children and took some persuading to return.

Hind spoke to Muchena, Naison Sampindi and Eunice Kachiti. Kachiti, she wrote later, had seen two men studying the fire with unusually narrow, elongated torches. None of the three doubted what they had seen: ghosts, spirits of the ancestors, most likely a shave, a lost spirit whose descendants had not done their duty by him. None had heard of visitors from space, and all were openly sceptical that men had been to the moon. When Hind put it to Muchena that his ancestors wore furs and skins, not silver coveralls, he agreed, and added, “but times change”.

She filed one more statement under the same heading, with a question mark. Jakob Niewergelt, a mechanical engineer, managed a sawmill in Mutare, nine kilometres away. On a clear weekday morning that August, probably the week after, he was halfway through his ten o’clock tea when a white point flashed high overhead, “so bright that it hit the eyes even without looking up”. A clerk noticed it too. Moments later the man on the radial arm saw outside came in to say it had stopped dead. The motor was cool, not jammed, and would not turn. Dismantled, its armature solder had melted and run into the coil. The electrical engineers he called in had no explanation, and when he mentioned the flying saucer stories going round Mutare they shook their heads. Every motor inside the building had run on as normal. Niewergelt kept this one, and offered Hind photographs.