She looked up at her acacia tree. There could be a snake in the tree for all she knew; nature was full of snake-like shapes and colours-long, sinuous twigs and boughs, snake-coloured grass that moved in the wind just as a snake might move. Concealment was easy. So snakes could watch us silently, their tongues flickering in and out to pick up our scent, their tiny, pitch-black eyes bright with evil; they were there, but the best way to deal with snakes was not to deal with them-Mma Ramotswe was sure of that. If we left snakes alone, then they kept away from us. It was only when we intruded on their world that they bit us, and who could blame them for that? It was the same with life in general, thought Mma Ramotswe. If we worried away at troublesome issues, we often only ended up making things worse. It was far better to let things sort themselves out.

She moved away from the acacia tree and began to make her way slowly back to the house. It was a fine day-not too warm, but with a gentle, almost undetectable breeze that touched the skin with the lightness of a feather. Such a wind would leave the sand where it lay, unlike those hot winds, laced with dust and grit, that made the eyes water and smart. It was a good day for walking, thought Mma Ramotswe, and today would be the first day she would walk to the office and back again in the late afternoon.

Mma Ramotswe was scrupulously honest, but this did not mean that she was above self-delusion. Had she examined her motives, then she might have been moved to confess that the real reason for walking to work was not so much a determination not to become lazy, but rather a realisation that for the time being it would be best not to use the tiny white van. If she did so, then Mr. J.L.B. Matekoni would be sure to hear the noise and would insist on examining the van to see what could be done. And if he did that, then she was certain that the loyal vehicle would be condemned.

That she did not want, and so the decision to walk to work was duly announced to Mr. J.L.B. Matekoni.

“That is very good,” he said. “If people walked to work, then they would save a lot of petrol. There would also be fewer cars on the road and not so many traffic jams.”

“And less work for mechanics?” added Mma Ramotswe.

Mr. J.L.B. Matekoni shook his head. “There is always enough work for mechanics,” he said. “Even if everybody walked, there would still be machines to go wrong.” He thought for a moment. “And there will always be work for mechanics fixing the bad work that other mechanics have done.”

They looked at one another. There was no doubt about his meaning; he was forever repairing the mistakes of his apprentices, as he had recently told Mma Ramotswe. She said nothing. She was hoping that he would not say anything about the tiny white van; she would confront that problem later. There would be some solution-perhaps a discreet visit to another garage, where the van might be fixed without Mr. J.L.B. Matekoni's ever knowing about it. It was even possible that the noise might disappear of its own accord; some engine noises were intermittent, the result of an occlusion of a fuel pipe, perhaps, a tiny piece of grit in the wrong place-there were many innocent explanations. With any luck, this would be the case with the current noise; one never knew with vehicles, as with life in general.

She left home in good time. The journey from Zebra Drive to the offices of the No. 1 Ladies' Detective Agency, shared with Tlokweng Road Speedy Motors, took about ten minutes or less by car, but on foot it would take at least forty minutes. Mma Ramotswe decided to allow an hour, although it would not matter too much if she took longer; her first appointment, with Mr. Molofololo, was not until eleven o'clock, and there would not be much to do before then. Mma Makutsi would have collected the mail, such as it was, and done whatever filing was left over from yesterday. There were also one or two minor cases that her assistant was working on, and she might busy herself with writing reports on these. Mma Makutsi was an enthusiastic writer of reports and maintained a bulging file labelled Incidental and Interim Reports that served little purpose in Mma Ramotswe's view, but that kept her busy at slack times. Mma Ramotswe thought of this file as Mma Makutsi's diary, but never described it as such. Her assistant, she remembered, was temperamental, and Mma Ramotswe had not forgotten that she had handed in her resignation not all that long ago. Even if she had stayed out of the office for less than a day, and had returned as if nothing had happened, Mma Ramotswe reminded herself that Mma Makutsi had no real need to work now that she was engaged to be married to Mr. Phuti Radiphuti, proprietor of the Double Comfort Furniture Shop and, as such, a man of considerable means. So she was careful not to offend her sometimes prickly assistant, and calling the Incidental and Interim Reports file a diary would undoubtedly have been very offensive.

The walk down Zebra Drive itself was uneventful. Her neighbour's dogs, those strange yellow dogs that Mma Ramotswe did not particularly like, barked at her as if she was any other passerby, running along the fence at the side of the neighbour's property, baring their teeth in impotent anger. She saw a curtain move in the neighbour's window and heard a shout as the dogs were called in; she waved, and the neighbour returned her greeting, a quick movement of a hand in a still-darkened room.

At the top of Zebra Drive there was more traffic, and she had to wait a few moments before she crossed to the other side of the road. The day still had the early morning feel about it, and the air was still sharp with a whiff of wood smoke. There were small huddles of people waiting beside the road for the early minibuses to sway past and a few others walking; domestic employees, Mma Ramotswe thought-cooks, maids, nannies of children-making their way to the well-set houses in the roads near Maru-a-Pula School. One of the women she recognised, a traditionally built woman like herself, who came from somewhere near Kgale Junction and who had served Mma Ramotswe tea when she had called on the principal of Maru-a-Pula to discuss with him the possibility of her taking part in a careers fair at the school.

“Some of the younger students have put down private detective on their careers form,” the principal explained. “So I thought that we should give them an idea of what such work entailed. And you, Mma Ramotswe, are the only private detective in Botswana, are you not?”

“I am always happy to help the school, Mr. Taylor,” she said. “But I am not sure if this is a good idea. If I tell them that it is a good thing to be, then they will want to do this job that I am doing. But where will the work come from?”

The principal listened carefully. “But Botswana is growing, Mma Ramotswe. There are many things happening in this country. Surely there will be work for more private detectives.”

Mma Ramotswe thought about this as the traditionally built woman from the school kitchens poured their tea. She looked at the woman, who smiled back at her; there was much that could be said without speaking, especially amongst women. A glance, a movement of the head, a slight shift in pose-all of these could convey a message as eloquently, as volubly, as words might do. The woman wanted to say something, thought Mma Ramotswe, but could not do so in this formal setting. She looked at the woman, but the moment had passed and the principal had asked a question that needed to be answered.

“Do you not agree with me, Mma Ramotswe?” asked the principal, passing Mma Ramotswe her tea cup. “If there is lots of business going on, then there will surely be temptations. Surely there is a need for people to look into that sort of thing.”

“That is true, Rra,” Mma Ramotswe said. “And I am sometimes asked to check up on dishonest employees. But not all that often.” She paused. “I am mostly concerned with little things. With the small problems of people's lives.”