“Oh, they don’t worry about that down here. There’s not much locking up done in these parts. As I say, at ten minutes to three Agnes was alone in the house. That she never left it is clear, for she was in her cap and apron still when we found her body.”

“I suppose you can tell roughly the time of death?”

“Doctor Griffith won’t commit himself. Between two o’clock and four thirty, is his official medical verdict.”

“How was she killed?”

“She was first stunned by a blow on the back of the head. Afterwards an ordinary kitchen skewer, sharpened to a fine point, was thrust in the base of the skull, causing instantaneous death.”

I lit a cigarette. It was not a nice picture.

“Pretty cold-blooded,” I said.

“Oh yes, yes, that was indicated.”

I inhaled deeply.

“Who did it?” I said. “And why?”

“I don’t suppose,” said Nash slowly, “that we shall ever know exactly why. But we can guess.”

“She knew something?”

“She knew something.”

“She didn’t give anyone here a hint?”

“As far as I can make out, no. She’s been upset, so the cook says, ever since Mrs. Symmington’s death, and according to this Rose, she’s been getting more and more worried, and kept saying she didn’t know what she ought to do.”

He gave a short exasperated sigh.

“It’s always the way. They won’t come to us. They’ve got that deep-seated prejudice against ‘being mixed up with the police.’ If she’d come along and told us what was worrying her, she’d be alive today.”

“Didn’t she give the other woman any hint?”

“No, or so Rose says, and I’m inclined to believe her. For if she had, Rose would have blurted it out at once with a good many fancy embellishments of her own.”

“It’s maddening,” I said, “not to know.”

“We can still guess, Mr. Burton. To begin with, it can’t be anything very defionite. It’s got to be the sort of thing that you think over, and as you think it over, your uneasiness grows. You see what I mean?”

“Yes.”

“Actually, I think I know what it was.”

I looked at him with respect.

“That’s good work, superintendent.”

“Well, you see, Mr. Burton, I know something that you don’t. On the afternoon that Mrs. Symmington committed suicide both maids were supposed to be out. It was their day out. But actually Agnes came back to the house.”

“You know that?”