The two old friends embraced and then Mma Ramotswe took Gwithie’s hand and pressed it, not once but several times. No words were exchanged, but the gesture of sympathy was understood. They had both lost the one thing in this life that is hardest to lose.

They went into the garden at the side of the house, crossing an expanse of grass that was dominated by a large jacaranda tree whose umbrella branches stretched out to provide an enticing circle of shade. In spite of the late dry season, the beds around the edge of the grass still had colour, surviving on the tiny amounts of water doled out to them by a drip-feed system of irrigation. The husbandry of water was well understood here: the using of every precious drop, the giving of water to those plants that needed it while the waxy desert plants like cacti were left to wait until the rain eventually brought them relief.

They made their way to the shade and sat down on chairs arranged around a low wooden table. On a tray by one of the chairs was a teapot with two cups.

‘In case of visitors,’ said Gwithie, pointing to the extra cup.

‘Very wise,’ said Mma Ramotswe. ‘Tea and cake is always…’ She had not intended to mention cake, but somehow it came out and she felt embarrassed.

‘Oh,’ said Gwithie. ‘Cake. Yes, well, I must do some more baking. I had one last week but we had the grandchildren in the house and cake doesn’t seem to last very long when children are in the house.’

‘Of course.’ Mma Ramotswe laughed, but she was disappointed. She could always bake herself a fruitcake – she had copied out Mma Potokwani’s recipe by hand into her own recipe book and she made a perfectly good version herself – but somehow the eating of one’s own cake was different from the eating of another’s.

‘Next time you come to see me,’ said Gwithie, ‘I promise you we shall have cake. Several slices, in fact.’

As her friend poured the tea, Mma Ramotswe looked out over the garden. Beyond the trees at its edge, the ground rose up to make a ridge, and beyond that were the hills looking down over the game reserve. There was no other building in sight. It was a small corner of undisturbed bush – Botswana in its untouched state. This was the land that Obed Ramotswe had known: the grey-green acacia scrub that ran for hundreds of miles along the country’s border to the east and, to the west, into the great Kalahari. This was the land over which the great dome of African sky presided; the sky that would, they all hoped, soon fill with towering, rain-filled thunderclouds from somewhere far away – the annual gift of the wetter and more temperate lands beyond their borders.

‘Rain,’ remarked Mma Ramotswe. She did not need to say anything more.