“There is another explanation that you don’t seem to want to address,” I said. “That the person who stabbed Tony Summers wiped the weapon clean of his or her own fingerprints, made sure there was plenty of blood on it and left it on the floor for Belinda to pick up.”

“That would be a possibility,” he said, giving me a long stare with those shrewd little eyes. “So that would indicate someone who wanted to incriminate Miss Warburton-Stoke.”

“Exactly,” I said. “That is exactly what she suggested earlier.”

His gaze moved back to Belinda.

“As I explained before, my uncle, Sir Francis Knott, is seething that I was left my grandmother’s estate. If I were to die I expect it would come to him.”

There was another long pause. The log on the fire shifted again, sending up sparks.

“The local police have checked on your uncle. Unfortunately for you he has a perfect alibi,” he said. “It has been verified that his boat was at its mooring across the river in Padstow all yesterday evening and that he was playing dominoes in the pub with a group of men until closing time.”

“Oh. I see.” Belinda looked crestfallen. “How annoying.”

“You wanted your uncle to be arrested for a crime?”

“No, but I wanted you to find someone else who had a good motive so you didn’t think it was me.”

“Which brings me to my next question: can you think of anyone else who might dislike you enough to pin a crime on you?”

My mind skipped unbidden to that time in the dell and what Rose had told us about Tony. If I said something, it gave Rose a good motive for murder. I decided to remain silent at this moment.

“I really can’t,” Belinda said. “As I told you before, I have had no real contact with the occupants of this house since I was fourteen and in those days we all got along well, having great adventures messing about on the river.”

“And it appears that you are the only guests in the house. The only outsiders in the immediate environment. We will naturally be checking on the backgrounds of all the servants,” the inspector said. “And any other suspicious people seen in the neighborhood, although this hardly looks like a crime committed by a member of the lower classes. The person would be taking a huge risk to steal the dagger from the wall in the first place and then be seen in the corridor of a guest’s bedroom.”

“One small point,” I said, making him swivel back to me rapidly. “Miss Warburton-Stoke’s window was open when I saw the room. She told me she had closed the window because it was raining hard that night.”

“So you are suggesting . . .”

“That someone could have come in from the outside, and climbed up to her window.”

“An outsider, you mean?”

I nodded.