THE NEXT MORNING, over breakfast, Mma Ramotswe announced to Mr. J.L.B. Matekoni that she would be walking to work that day. She had taken the decision an hour or so earlier, in the middle of her habitual stroll around her garden, shortly after inspecting the pawpaw trees that marked the boundary between her plot and the small piece of wasteland that ran behind it. She had planted the trees herself when first she had come to Zebra Drive and the garden had been nothing, just hard earth, scrub, and sour weeds. Now the trees were laden with fruit, heavy yellow orbs that she would shortly pick and enjoy. She liked pawpaw, but neither Mr. J.L.B. Matekoni nor the children did, and so these would be for her alone, a private treat, served with orange juice and topped, perhaps, with a small sprinkling of sugar.

Beside the pawpaw trees was an acacia tree in which birds liked to pause on their journeys and in which Mr. J.L.B. Matekoni had once seen a long green snake, curled around a branch, its tail hanging down like an elongated twig to be brushed against by some unwary person passing below. The sighting of snakes was an everyday occurrence in Botswana, but the unfortunate creatures were never left alone. Mma Ramotswe did not like to kill them and had thoroughly agreed with a recent public plea from the Wildlife Department that people should refrain from doing anything about snakes unless they actually came into the house. They have their place, said the official, and if there were no snakes, then there would be many more rats, and all the rats would make quick work of the patiently gathered harvest.