“Oh yes, you do. The ants are watching us, you see, Mma. They are watching us all the time. If we let down our guard, the ants will make their move and then…goodbye Botswana.”

They had reached the end of the corridor and were standing outside a door marked Records. “This is the place,” said the clerk. “This is where we will find what you’re looking for, Mma.”

The clerk unlocked the door. The room inside was a large one, and lined on all four walls with high shelving. Box files and ledgers took up most of the shelf space, although here and there were stacks of papers neatly bundled and tied with red tape.

“That is the famous red tape,” said the clerk, pointing to the bundles of documents. “You have heard the expression ‘red tape,’ Mma?”

“I have heard it,” said Mma Ramotswe. “Red tape is always making things go slower.”

“We have big supplies of it here,” said the clerk, smiling. “Some people find it very useful. But remind me, Mma, what is the address of this place you are enquiring about?”

She gave him the details. It was Plot 2408 Zebra Drive, and she gave him the dates she was interested in.

The clerk listened attentively. Then he said, “Can you time me, Mma?”

“You want me to time how long it takes you to find what you’re looking for?”

He nodded brightly. “That’s the idea, Mma. They call that a ‘time and motion study.’ ”

She looked at her watch. “Very well, Rra. I’m timing you.”

The clerk stepped sharply forward to one of the higher shelves and took down a box file. Opening it, he ruffled through a sheaf of documents before extracting one of them.

“Stop the clock, Mma,” he called.

“That was forty-five seconds, Rra.”

He looked at her proudly. “And here is the list of transactions to do with Plot 2408 Zebra Drive. It covers the period from the construction of the house, through its various tenancies, and then finally to its sale when the Commission decided to reduce its housing stock.” He handed the document to her. “It is all there, Mma. The whole early history of that place.”

She looked at the paper. It was easy to interpret, and the information she was looking for leapt to her eyes immediately.

“I see that there was a lease to the hospital,” she said, pointing to the line in question.

The clerk looked over her shoulder. “Yes,” he said. “The Commission let the house to the hospital authorities for twelve years in all. And there, you see, just down at the bottom is the list of the sub-tenants that the hospital arranged. We always insisted on knowing who had signed a sub-lease.”

She looked at the names. The one she was looking for was there. Handing the paper back to the clerk, she thanked him for his helpfulness.