Mighty looked puzzled. Glancing over his shoulder to check that they could not be overheard by Tebogo, he assured her that there was no question but that Tebogo had looked after Mrs. Grant. “It is in the book,” he said. “And he remembers her.” He gestured to the letter. “That letter is signed by Mrs. Grant, isn’t it? Yes, look at it. That says Grant.”

Mma Ramotswe frowned. “I know,” she whispered. “I know that. But that lady in the picture is not Mrs. Grant. I have her photograph with my things in the room. I’ll show you, if you like. That is not the lady.”

Mighty made a gesture of helplessness. “I don’t see how this can be,” he said.

Mma Ramotswe fiddled anxiously with the papers. “I don’t know what to do,” she said. “I cannot pay the money to the wrong man. I have my duty to Mrs. Grant’s lawyer, a certain Mr. Maxwell. He is my client, Rra. Can you see that?”

Mighty nodded, again looking furtively at Tebogo. “I understand, Mma. But I just don’t see how this can be. A lady called Mrs. Grant came to this camp …”

Mma Ramotswe took hold of his forearm. “Hold on, Rra. You said that a lady called Mrs. Grant came to the camp …”

“I did. And I have already shown you the evidence of that.”

Mma Ramotswe drew him further away from the other two, who were still engaged in their observation of the monkeys. “A lady called Mrs. Grant,” said Mma Ramotswe. She spoke slowly and deliberately, as if testing each word. “Do you think that Grant is a common name, Rra? I’ve certainly seen it before. Have you?”

Mighty considered this. “I think so,” he said. “We’ve had other Grants before. Maybe it’s a common name in America, like … like Tebogo in Botswana. Or Ramotswe …”

Mma Ramotswe smiled, but did not let the joke distract her. “You’ve had other Grants before, you say. But not at the same time.”

“No, not at the same time.”

It was all falling into place. “Mighty,” she said, “what if there were two Mma Ramotswes? Or two Mma Grants?”

Mighty frowned. “Two Mma Ramotswes?” He stared at her, and then he put his hand to his cheek and stroked it. “Oh,” he said. Then, “Oh,” again.

“Oh,” echoed Mma Ramotswe. She looked in his eyes. He was a sharp-witted man. He understood. But there was one final piece of the jigsaw to fit into place. “Can you think of another camp with an animal in its name?”

Mighty answered quickly. “Our neighbour,” he said. “Three miles away. Lion’s Tail Camp.”

“Can you take me there?” asked Mma Ramotswe.

Mighty looked doubtful. “Right now?”

“Yes. Right now, Rra.”

“It’s getting late. We’ll have to go by boat.”

“I’m ready to go.”