The trader picked out another worm from her bag and popped it into her mouth.

"I saw them," she said. "They went over to the cinema. Then they went off somewhere else. I didn't notice where they were going."

Mma Ramotswe smiled. "You should be a detective," she said.

"Like you," said the woman simply.

This surprised Mma Ramotswe. She was quite well-known, but she had not necessarily expected a street trader to know who she was. She reached into her handbag and extracted a ten-pula note, which she pressed into the woman's hand.

"Thank you," she said. "That's a fee from me. And I hope you will be able to help me again some time."

The woman seemed delighted.

"I can tell you everything," she said. "I am the eyes of this place. This morning, for example, do you want to know who was talking to whom just over there? Do you know? You'd be surprised if I told you."

"Some other time," said Mma Ramotswe. "I'll be in touch."

There was no point in trying to find where Nandira had got to now, but there was every point in following up the information that she already had. So Mma Ramotswe went to the cinema and enquired as to the time of that evening's performance, which is what she concluded the two girls had been doing. Then she returned to the little white van and drove home, to prepare herself for an early supper and an outing to the cinema. She had seen the name of the film; it was not something that she wanted to sit through, but it had been at least a year since she had been to the cinema and she found that she was looking forward to the prospect.

Mr Patel telephoned before she left.

"My daughter has said that she is going out to see a friend about some homework," he said peevishly. "She is lying to me again."

"Yes," said Mma Ramotswe. "I'm afraid that she is. But I know where she's going and I shall be there, don't you worry."

"She is going to see this Jack?" shouted Mr Patel. "She is meeting this boy?"

"Probably," said Mma Ramotswe. "But there is no point in your upsetting yourself. I will give you a report tomorrow."

"Early-early, please," said Mr Patel. "I am always up at six, sharp-sharp-"

THERE WERE very few people in the cinema when Mma Ramotswe arrived. She chose a seat in the penultimate row, at the back. This gave her a good view of the door through which anybody entering the auditorium would have to pass, and even if Nandira and Jack came in after the lights had gone down, it would still be possible for Mma Ramotswe to pick them out.

Mma Ramotswe recognised several of the customers. Her butcher arrived shortly after she did, and he and his wife gave her a friendly wave. Then there was one of the teachers from the school and the woman who ran the aerobics class at the President Hotel. Finally there was the Catholic bishop, who arrived by himself and ate popcorn loudly in the front row.

Nandira arrived five minutes before the first part of the programme was about to start. She was by herself, and she stood for a moment in the door, looking around her. Mma Ramotswe felt her eyes rest on her, and she looked down quickly, as if inspecting the floor for something. After a moment or two she looked up again, and saw that the girl was still looking at her.

Mma Ramotswe looked down at the floor again, and saw a discarded ticket, which she reached down to pick up.

Nandira walked purposefully across the auditorium to Mma Ramotswe's row and sat down in the seat next to her.

"Evening, Mma," she said politely. "Is this seat taken?"

Mma Ramotswe looked up, as if surprised.

"There is nobody there," she said. "It is quite free."

Nandira sat down.

"I am looking forward to this film," she said pleasantly. "I have wanted to see it for a long time."

"Good," said Mma Ramotswe. "It is nice to see a film that you've always wanted to see."

There was a silence. The girl was looking at her, and Mma Ramotswe felt quite uncomfortable. What would Clovis Andersen have done in such circumstances? She was sure that he said something about this sort of thing, but she could not quite remember what it was. This was where the subject crowded you, rather than the other way round.

"I saw you this afternoon," said Nandira. "I saw you at Maru-a-Pula."

"Ah, yes," said Mma Ramotswe. "I was waiting for somebody."

"Then I saw you in the Book Centre," Nandira continued. "You were looking at a book."

"That's right," said Mma Ramotswe. "I was thinking of buying a book."

"Then you asked Mma Bapitse about me," Nandira said quietly. "She's that trader. She told me that you were asking about me."

Mma Ramotswe made a mental note to be careful of Mma Bapitse in the future.

"So, why are you following me?" asked Nandira, turning in her seat to stare at Mma Ramotswe.

Mma Ramotswe thought quickly. There was no point in denying it, and she may as well try to make the most of a difficult situation. So she told Nandira about her father's anxieties and how he had approached her.

"He wants to find out whether you're seeing boys," she said. "He's worried about it."

Nandira looked pleased.

"Well, if he's worried, he's only got himself to blame if I keep going out with boys."

"And are you?" asked Mma Ramotswe. "Are you going out with lots of boys?"

Nandira hesitated. Then, quietly: "No. Not really."

"But what about this Jack?" asked Mma Ramotswe.

"Who's he?"

For a moment it seemed as if Nandira was not going to reply. Here was another adult trying to pry into her private life, and yet there was something about Mma Ramotswe that she trusted. Perhaps she could be useful; perhaps…

"Jack doesn't exist," she said quietly. "I made him up."

"Why?"

Nandira shrugged. "I want them-my family-to think I've got a boyfriend," she said. "I want them to think there's somebody I chose, not somebody they thought right for me." She paused. "Do you understand that?"

Mma Ramotswe thought for a moment. She felt sorry for this poor, overprotected girl, and imagined just how in such circumstances one might want to pretend to have a boyfriend.

"Yes," she said, laying a hand on Nandira's arm. "I understand."

Nandira fidgeted with her watchstrap.

"Are you going to tell him?" she asked.

"Well, do I have much choice?" asked Mma Ramotswe. "I can hardly say that I've seen you with a boy called Jack when he doesn't really exist."

Nandira sighed. "Well, I suppose I've asked for it. It's been a silly game." She paused. "But once he realises that there's nothing in it, do you think that he might let me have a bit more freedom? Do you think that he might let me live my life for a little without having to tell him how I spend every single minute?"

"I could try to persuade him," said Mma Ramotswe. "I don't know whether he'll listen to me. But I could try."

"Please do," said Nandira. "Please try."

They watched the film together, and both enjoyed it. Then Mma Ramotswe drove Nandira back in her tiny white van, in a companionable silence, and dropped her at the gate in the high white wall. The girl stood and watched as the van drove off, and then she turned and pressed the bell.

"Patel place here. What do you want?"

"Freedom," she muttered under her breath, and then, more loudly: "It's me, Papa. I'm home now."

MMA RAMOTSWE telephoned Mr Patel early the next morning, as she had promised to do. She explained to him that it would be better for her to speak to him at home, rather than to explain matters over the telephone.

"You've got bad news for me," he said, his voice rising. "You are going to be telling me something bad-bad. Oh my God! What is it?"

Mma Ramotswe reassured him that the news was not bad, but she still found him looking anxious when she was shown into his study half an hour later.