A small brass plaque with the name Puso Kirby was attached towards the base of the rubbing stone. Underneath were the words: Light of Our Lives.

Mma Ramotswe took her friend’s hand. ‘Yes, Mma,’ she said. ‘This is his place.’

Gwithie was looking out over the waters of the lake. ‘You know, Mma,’ she said, ‘on the day that we lost him we heard a leopard nearby. We very rarely hear those creatures – they are so shy and secretive – but we heard a leopard. There is no mistaking them. And it was here when we buried him.’

Mma Ramotswe said nothing, but she pressed her friend’s hand in sympathy.

‘And then,’ Gwithie continued, ‘there was an extraordinary thing. I don’t expect people to believe it, but it happened. When the children came, much later, to see their father’s grave, as we were walking down here, we saw the leopard. He was following us, but we felt no fear – not for one moment.’

Mma Ramotswe looked at her. ‘Do you think it was him? His spirit?’

Gwithie lowered her eyes, and her head moved slightly. Her voice was quiet. ‘Why should I not think that?’

‘There is no reason why you should not think that,’ said Mma Ramotswe. ‘It is a lovely thing to believe. He loved wild animals. They were his work, weren’t they? He loved the bush. He loved the rocks that leopards love. So that is where your son must be, Mma. He must be. We are always in the place we love, Mma. We never leave it.’

They moved away, with Mma Ramotswe still holding Gwithie’s hand until they turned the corner, and the stone, with its heartfelt inscription, was no longer in sight. The light of our lives. Yes, thought Mma Ramotswe. That is what we should be to one another: light that shines whatever the darkness of loss. Always.

It did not seem right to return to the Molapo case until much later, when she had left her friend and was travelling back on the final stretch of road towards Gaborone. Then she allowed herself to wonder how she would be able to prove what might be the truth. One slip of the tongue by a young man could hardly be considered evidence sufficient to unmask an imposter. And then a further thought came: what if it were simply a mistake on his part? Liso Molapo – the real Liso Molapo – had not seen his mother for a long time and might easily call his aunt by that name because he viewed her as a substitute for the mother he no longer had. That was entirely plausible and, if true, it meant that she was no further along the road to sorting out this affair.