“Therefore Camber is guilty?”

“On the contrary, therefore Camber is innocent!”

“What!”

“You are persistently overlooking one little point, Knox,” said Harley, mounting the steps on to the gravel path. “I spoke of the seventh yew tree from the northeast corner of the garden.”

“Well?”

“Well, my dear fellow, surely you observed that the bullet was embedded in the ninth?”

I was still groping for the significance of this point when, re-crossing the hall, we entered the library again, to find Inspector Aylesbury posed squarely before the mantelpiece stating his case to Wessex.

“You see,” he was saying, in his most oratorical manner, as we entered, “every little detail fits perfectly into place. For instance, I find that a woman, called Mrs. Powis, who for the past two years had acted as housekeeper at the Guest House and never taken a holiday, was sent away recently to her married daughter in London. See what that means? Her room is at the back of the house, and her evidence would have been fatal. Ah Tsong, of course, is a liar. I made up my mind about that the moment I clapped eyes on him. Mrs. Camber is the only innocent party. She was asleep in the front of the house when the shot was fired, and I believe her when she says that she cannot swear to the matter of distance.”

“A very interesting case, Inspector,” said Wessex, glancing at Harley. “I have not examined the body yet, but I understand that it was a clean wound through the head.”

“The bullet entered at the juncture of the nasal and frontal bones,” explained Harley, rapidly, “and it came out between the base of the occipital and first cervical. Without going into unpleasant surgical details, the wound was a perfectly straight one. There was no ricochet.”