Above the slightly built woman, on the wall of the farmhouse near a small town in South Africa’s North West province, is a framed photograph. It shows her wearing a stylish sunshine-yellow dress, black hair cascading onto her shoulders. The man alongside her is wearing a smart navy suit and tie, giving a thumbs-up to the camera. “I don’t know why Johan’s smiling,” she says softly, with a smile of her own. “He hated wearing a suit. He always called himself a ‘man of the dirt.’ This dirt,” she adds, pointing toward an open doorway, to dry fields dotted with beef cattle. On a summer night in 2019, Karlien and Johan van Wyk, along with their 6-year-old daughter, fell asleep on a couch in their living room while watching television. Their two other daughters, 2 and 4, were asleep in a downstairs bedroom. Karlien, 7-months pregnant at the time with …