“Has he written any prescriptions for you lately?”

This time the question genuinely surprised her.

“No,” she said. “Can’t you tell? I’m the picture of health.”

“A prescription with your name on it was taken to a pharmacist in the middle of Otterbridge today.”

“It must be a coincidence,” she said. “ Really, I haven’t been to the doctor for years.”

“It was a fictional prescription,” he said. “Made out for someone else entirely. But Dr. Laidlaw chose your name. Why was that, do you think? Why, of all the patients in the practise, was yours the first to come into his mind?”

“I don’t bloody know!” she said, but she was secretly delighted.

“When did you last see Dr. Laidlaw?”

“I can’t remember.”

There was a pause. Mary lit another cigarette. It was very late and she had not slept well on Sophie’s sofa. She yawned.

“We’ve had some difficulty in finding you during the last few days,” Ramsay said. “Can you give me some idea of where you’ve been?”

“Be more specific,” Mary said, playing for time.

“What about Tuesday morning?” Ramsay said. “ That’s when Charlie Elliot was murdered.”

But if he hoped to frighten her he did not succeed. She seemed to take a keen interest in the questions. She was wary. But she did not feel under any personal threat.

“I talked to you,” she said. “You came into the café in town and I saw you there.”

“What about earlier that morning?” he asked. “ Between five and six-thirty. Where were you then?”

“I was at home,” she said. “ I was restless and couldn’t sleep. I started to do some work.”

What’s wrong with all these women? Ramsay thought, remembering that Stella Laidlaw, too, had complained of being restless. Do they all suffer from insomnia?

“Can anyone confirm that you were at home?” he asked.

“I was typing,” she said. “Someone else in the house might have heard it.”

“Why have you spent so little time in the office?” he asked. It was a final question. He expected to get nothing else out of her. He was profoundly disappointed.

So she told Ramsay a little about her story. It was a relief to have something to tell him without pretence, and as she spoke with immense enthusiasm he became more interested.

“If it comes to anything,” he said, “you should let me know. It might be a police matter.”

“Yes,” she said. Perhaps he wasn’t such a bad policeman after all. She was tempted just for a moment to trust him. Then she remembered Max, sobbing and overwrought, and knew that this was just another trick to put her off her guard.