Caswall was genuinely surprised when he saw Lady Arabella, though he need not have been, after what had already occurred in the same way. The look of surprise on his face was so much greater than Lady Arabella had expected--though she thought she was prepared to meet anything that might occur--that she stood still, in sheer amazement. Cold-blooded as she was and ready for all social emergencies, she was nonplussed how to go on. She was plucky, however, and began to speak at once, although she had not the slightest idea what she was going to say.

"I came to offer you my very warm sympathy with the grief you have so lately experienced."

"My grief? I'm afraid I must be very dull; but I really do not understand."

Already she felt at a disadvantage, and hesitated.

"I mean about the old man who died so suddenly--your old. . . retainer."

Caswall's face relaxed something of its puzzled concentration.

"Oh, he was only a servant; and he had over-stayed his three-score and ten years by something like twenty years. He must have been ninety!"

"Still, as an old servant. . . "

Caswall's words were not so cold as their inflection.

"I never interfere with servants. He was kept on here merely because he had been so long on the premises. I suppose the steward thought it might make him unpopular if the old fellow had been dismissed."

How on earth was she to proceed on such a task as hers if this was the utmost geniality she could expect? So she at once tried another tack--this time a personal one.

"I am sorry I disturbed you. I am really not unconventional--though certainly no slave to convention. Still there are limits. . . it is bad enough to intrude in this way, and I do not know what you can say or think of the time selected, for the intrusion."

After all, Edgar Caswall was a gentleman by custom and habit, so he rose to the occasion.

"I can only say, Lady Arabella, that you are always welcome at any time you may deign to honour my house with your presence."

She smiled at him sweetly.

"Thank you SO much. You DO put one at ease. My breach of convention makes me glad rather than sorry. I feel that I can open my heart to you about anything."

Forthwith she proceeded to tell him about Oolanga and his strange suspicions of her honesty. Caswall laughed and made her explain all the details. His final comment was enlightening.

"Let me give you a word of advice: If you have the slightest fault to find with that infernal nigger, shoot him at sight. A swelled- headed nigger, with a bee in his bonnet, is one of the worst difficulties in the world to deal with. So better make a clean job of it, and wipe him out at once!"

"But what about the law, Mr. Caswall?"

"Oh, the law doesn't concern itself much about dead niggers. A few more or less do not matter. To my mind it's rather a relief!"

"I'm afraid of you," was her only comment, made with a sweet smile and in a soft voice.

"All right," he said, "let us leave it at that. Anyhow, we shall be rid of one of them!"

"I don't love niggers any more than you do," she replied, "and I suppose one mustn't be too particular where that sort of cleaning up is concerned." Then she changed in voice and manner, and asked genially: "And now tell me, am I forgiven?"

"You are, dear lady--if there is anything to forgive."

As he spoke, seeing that she had moved to go, he came to the door with her, and in the most natural way accompanied her downstairs. He passed through the hall with her and down the avenue. As he went back to the house, she smiled to herself.

"Well, that is all right. I don't think the morning has been altogether thrown away."

And she walked slowly back to Diana's Grove.

Adam Salton followed the line of the Brow, and refreshed his memory as to the various localities. He got home to Lesser Hill just as Sir Nathaniel was beginning lunch. Mr. Salton had gone to Walsall to keep an early appointment; so he was all alone. When the meal was over--seeing in Adam's face that he had something to speak about--he followed into the study and shut the door.

When the two men had lighted their pipes, Sir Nathaniel began.

"I have remembered an interesting fact about Diana's Grove--there is, I have long understood, some strange mystery about that house. It may be of some interest, or it may be trivial, in such a tangled skein as we are trying to unravel."

"Please tell me all you know' or suspect. To begin, then, of what sort is the mystery--physical, mental, moral, historical, scientific, occult? Any kind of hint will help me."

"Quite right. I shall try to tell you what I think; but I have not put my thoughts on the subject in sequence, so you must forgive me if due order is not observed in my narration. I suppose you have seen the house at Diana's Grove?"

"The outside of it; but I have that in my mind's eye, and I can fit into my memory whatever you may mention."

"The house is very old--probably the first house of some sort that stood there was in the time of the Romans. This was probably renewed--perhaps several times at later periods. The house stands, or, rather, used to stand here when Mercia was a kingdom--I do not suppose that the basement can be later than the Norman Conquest. Some years ago, when I was President of the Mercian Archaeological Society, I went all over it very carefully. This was when it was purchased by Captain March. The house had then been done up, so as to be suitable for the bride. The basement is very strong,--almost as strong and as heavy as if it had been intended as a fortress. There are a whole series of rooms deep underground. One of them in particular struck me. The room itself is of considerable size, but the masonry is more than massive. In the middle of the room is a sunk well, built up to floor level and evidently going deep underground. There is no windlass nor any trace of there ever having been any--no rope--nothing. Now, we know that the Romans had wells of immense depth, from which the water was lifted by the 'old rag rope'; that at Woodhull used to be nearly a thousand feet. Here, then, we have simply an enormously deep well-hole. The door of the room was massive, and was fastened with a lock nearly a foot square. It was evidently intended for some kind of protection to someone or something; but no one in those days had ever heard of anyone having been allowed even to see the room. All this is E PROPOS of a suggestion on my part that the well-hole was a way by which the White Worm (whatever it was) went and came. At that time I would have had a search made--even excavation if necessary--at my own expense, but all suggestions were met with a prompt and explicit negative. So, of course, I took no further step in the matter. Then it died out of recollection--even of mine."

"Do you remember, sir," asked Adam, "what was the appearance of the room where the well-hole was? Was there furniture--in fact, any sort of thing in the room?"

"The only thing I remember was a sort of green light--very clouded, very dim--which came up from the well. Not a fixed light, but intermittent and irregular--quite unlike anything I had ever seen."

"Do you remember how you got into the well-room? Was there a separate door from outside, or was there any interior room or passage which opened into it?"

"I think there must have been some room with a way into it. I remember going up some steep steps; they must have been worn smooth by long use or something of the kind, for I could hardly keep my feet as I went up. Once I stumbled and nearly fell into the well- hole."

"Was there anything strange about the place--any queer smell, for instance?"

"Queer smell--yes! Like bilge or a rank swamp. It was distinctly nauseating; when I came out I felt as if I had just been going to be sick. I shall try back on my visit and see if I can recall any more of what I saw or felt."

"Then perhaps, sir, later in the day you will tell me anything you may chance to recollect."

"I shall be delighted, Adam. If your uncle has not returned by then, I'll join you in the study after dinner, and we can resume this interesting chat."