fallen asleep in a chair, poor girl. You know the house at Rotherfield, Malone. It was in the big hall. I sat by the fireplace, the room all draped in shadow, and my mind draped in shadow also. I should have sent her to bed, but she was lying back in her chair and I did not wish to wake her. It may have been one in the morning — I remember the moon shining through

the stained-glass window. I sat and I brooded. Then suddenly there came a noise.”

“Yes, sir?”

“It was low at first — just a ticking. Then it grew louder and more distinct — it was a clear rat-tat-tat. Now comes the queer coincidence, the sort of thing out of which legends grow when credulous folk have the shaping of them. You must know that my wife had a peculiar way of knocking at a door. It was really a little tune which she played with her fingers. I got into the same way so that we could each know when the other knocked. Well, it seemed to me — of course my mind was strained and abnormal — that the taps shaped themselves into the well-known rhythm of her knock. I couldn’t localise it. You can think how eagerly I tried. It was above me, somewhere on the woodwork. I lost sense of time. I daresay it was repeated a dozen times at least.”

“Oh, Dad, you never told me!”

“No, but I woke you up. I asked you to sit quiet with me for a little.”

“Yes, I remember that.”

“Well, we sat, but nothing happened. Not a sound more. Of course it was a delusion. Some insect in the wood; the ivy on the outer wall. My own brain furnished the rhythm. Thus do we make fools and children of ourselves. But it gave me an insight. I