“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 a 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?”