Mma Makutsi was uncertain. “There is not much point in sitting here,” she said. “We are really interested in what is going on in that house.”

She remembered Mma Ramotswe’s advice. The best source of information was undoubtedly the maids, if they could be persuaded to talk. It was now lunchtime, and the maids would be busy in the kitchen. But in an hour or so, they would have their own lunch break, and would come back to the servants’ quarters. And those could be reached quite easily, along the narrow sanitary lane that ran along the back of the properties. That would be the time to speak to them and to offer the crisp new fifty pula notes which Mma Ramotswe had issued her the previous evening.

The uncle wanted to accompany her, and Mma Makutsi had difficulty persuading him that she could go alone.

“It could be dangerous,” he said. “You might need protection.”

She brushed aside his objections. “Dangerous, Uncle? Since when has it been dangerous to talk to a couple of maids in the middle of Gaborone, in the middle of the day?”

He had had no answer to that, but he nonetheless looked anxious when she left him in the car and made her way along the lane to the back gate. He watched her hesitate behind the small, whitewashed building which formed the servants’ quarters, before making her way round to the door, and then he lost sight of her. He took out his pencil, glanced at the time, and made a note: Mma Makutsi enters servants’ quarters at 2:10 P.M.

THERE WERE two of them, just as she had anticipated. One of them was older than the other, and had crow’s-feet wrinkles at the side of her eyes. She was a comfortable, large-chested woman, dressed in a green maid’s dress and a pair of scuffed white shoes of the sort which nurses wear. The younger woman, who looked as if she was in her mid-twenties, Mma Makutsi’s own age, was wearing a red housecoat and had a sultry, spoiled face. In other clothes, and made-up, she would not have looked out of place as a bar girl. Perhaps she is one, thought Mma Makutsi.

The two women stared at her, the younger one quite rudely.

“Ko ko,” said Mma Makutsi, politely, using the greeting that could substitute for a knock when there was no door to be knocked upon. This was necessary, as although the women were not inside their house they were not quite outside either, being seated on two stools in the cramped open porch at the front of the building.

The older woman studied their visitor, raising her hand to shade her eyes against the harsh light of the early afternoon.

“Dumela, Mma. Are you well?”

The formal greetings were exchanged, and then there was silence. The younger woman poked at their small, blackened kettle with a stick.