“She says she went out later. She said the food was so bad that she decided to walk down to the town and have something to eat in a café. But she said that nothing was open except pubs because it was Sunday evening, and she wasn’t about to go into a common public house.”

“That’s interesting,” I said, “because she told me that she had spent the evening in, reading. And did she explain the knife in her pocket?”

“Miss Carrington was not stabbed, Lady Georgiana. She was drugged and then suffocated. If anyone carries a knife it seems to be irrelevant.” He gave an annoying half sniff, half snort through his nostrils. “And what possible motive could a foreign lady have for killing an Englishwoman she had never met?”

“The perfect motive, Chief Inspector,” I said. “She worships Princess Marina. She would do anything to protect her, and if she’d learned that Bobo Carrington had been Prince George’s mistress and that he may be the father of her child, she would stop at nothing to prevent that news from becoming public.”

He was staring at me as if he was digesting this information and it was beginning to make sense.

“And she was alone all evening with servants who aren’t the most attentive and who would have been having their own evening meal in a kitchen where they would not have heard or seen anything.”

Again I paused, letting him consider this.

I leaned forward in my chair. “Picture this, Chief Inspector. Bobo comes to the front door, demanding to see Princess Marina. Perhaps she has decided to come clean and tell Marina the truth about her and the prince. Perhaps her motive is not as pure and she wants money to stay mum about her story. But Princess Marina is not home so she tells the countess instead. And the countess decides she must not be allowed to leave. She puts Marina’s sleeping drops in the coffee and then finishes Bobo off by suffocating her.” I paused, then went on, “And she has all the time in the world because the servants find her disagreeable and are keeping well away.”

There was a long moment of silence, punctuated only by the loud tick of his clock on the wall. Then he nodded. “As you say, it does make sense.”