Mma Ramotswe remembered the doctors she had met all those years ago—those two doctors, twins, involved in a profitable fraud in which they shared only one medical qualification between them. Yes, doctors could be criminals. Those had been criminal doctors; they had shown no concern for the safety of their patients, just like those doctors one read about who deliberately killed their patients as if out of sheer bravado. Those stories were shocking because they represented the most extreme breach of trust imaginable, but it appeared that they were true. And for a moment Mma Ramotswe considered the terrible possibility that Boitelo had found herself working for one of those homicidal doctors, right here in Gaborone. That would be a powerful cause for fear; indeed, just to think of it made her flesh come up in goose bumps.

“Yes,” she answered. “I do think that. There have been some very wicked doctors who have even killed their patients.” She paused, hardly daring to ask the question. “You haven’t stumbled across something like that, Mma?”

She had hoped that Boitelo’s answer would be a swift denial, but it was not. For a moment the young woman seemed to dwell on the question, and then at last she answered. “Not quite,” she said.

Behind her, Mma Makutsi let out a little gasp. Mma Ramotswe had been to the doctor only a few days earlier and had been given a bottle of small white pills which she had been taking religiously. It would be so easy for a doctor to substitute something fatal, should he wish to do so, in the knowledge that his trusting patient would pop the poison into her mouth. But why would any doctor want to do that? What drove a doctor to kill the very person he was meant to save? Was it a madness of some sort; an urge that people have from time to time to do something utterly bizarre and out of character? She herself had felt that once or twice when she had been suddenly tempted to throw a tea-pot at Mr J.L.B. Matekoni. She had been astonished that such an outrageous thought had even entered her mind, but it had, and she had sat there wondering what would happen if she picked up the tea-pot from the table and threw it across the room at poor Mr J.L.B. Matekoni as he sat drinking his afternoon tea, his head full of thoughts of gearboxes and brakes, or whatever it was that Mr J.L.B. Matekoni’s head was full of. Of course she had not done it, and never would, but the thought had been there, an unwelcome visitor to her otherwise quite rational mind. Perhaps it was the same with those strange cases of the doctors who deliberately killed their patients. Perhaps …

“Not quite?” asked Mma Ramotswe. “Do you mean …”