The Groendal Reserve lies in the folds of the Groot Winterhoek mountains behind Uitenhage, steep kloofs and dense fynbos, close enough to Despatch for boys to camp there overnight and be fetched the next day. Four of them had camped there overnight: Peter Simpson, sixteen, a Despatch doctor’s son, with Jannie Bezuidenhout, Hugo Ferreira and a fourth friend Afrinews does not name. The morning was overcast. Mrs Simpson was due at midday, and the boys were doing what boys do while waiting to be fetched, which is looking at the far hills.

Something over there was glistening: a good way off, a spot on the slope was catching what light there was. While they puzzled over it, Jannie pointed. Two men had appeared, crossing the view from right to left. Poachers, the boys decided. Then they saw the men were wearing silver suits, and revised their guess to firemen. Hugo Ferreira’s verdict, as Hind printed it: “I thought their silver suits looked like aluminium foil.”

The men had come from the glistening thing. Halfway up the hill a third joined them, carrying what looked like a square silver suitcase. All three made for a fence, and the way they moved was wrong. They did not lean into the slope as a climber does; Peter Simpson was particular about that. They stayed upright and went up it “almost as though their legs were fins”, in Hind’s phrase. At the fence they climbed over, and the last man looked straight at the boys, who agreed afterwards that he must have seen them. Then the three reached the hilltop and were simply not there any more, and neither was the shining spot.

Hind heard about it by telephone while interviewing witnesses at Rosmead and Middelburg in the Karoo, and she and her travelling companion Peggy McLean drove straight to Despatch. Sergeant Chris Powell of the South African Police, who supplied her with many cases from Uitenhage and its surroundings, had been out to the glistening spot and found the ground trampled, with a depression in it. “That depression was not formed by anything normal,” he told her, “the marks were too symmetrical.” Somebody suggested mating turtles (tortoises, presumably, this far from the sea). The reserve’s trackers, who knew what those did to the ground, were not having it.

Powell went back with two geology lecturers from the University of Port Elizabeth, Russell Shone and Dave Glenister, released by a sceptical Professor Rust to account for the depressions. What came back was a description: nine separate impressions arranged symmetrically, Shone reported, with four small holes in them of the kind a tubular prong or tine might leave. The two geologists, Hind wrote, were obviously sceptical and yet impressed.

Hind set all this down twenty-two years later as an old case she could still see clearly. One detail, she said, had only come to light afterwards. The fynbos on that hillside stands over two metres high, and the boys had been able to see the three men across it at all, which meant, if the men were where the boys put them, that they had been moving above the bush rather than through it. Which leaves the small question nobody seems to have asked: why three men who could glide over two metres of fynbos should have bothered to climb a fence.

In 1979 an American tabloid, the National Enquirer, gave the case an award as the best and most impressive of its kind for 1978. Hind recorded the honour with an exclamation mark and left it at that.