The nunnery flourished for more than a century, when, in the time of Penda, who was the reactionary of heathendom, it fell into decay. In the meantime the doves, protected by religious feeling, had increased mightily, and were known in all Catholic communities. When King Offa ruled in Mercia, about a hundred and fifty years later, he restored Christianity, and under its protection the nunnery of St. Columba was restored and its doves flourished again. In process of time this religious house again fell into desuetude; but before it disappeared it had achieved a great name for good works, and in especial for the piety of its members. If deeds and prayers and hopes and earnest thinking leave anywhere any moral effect, Mercy Farm and all around it have almost the right to be considered holy ground."

"Thank you, sir," said Adam earnestly, and was silent. Sir Nathaniel understood.

After lunch that day, Adam casually asked Sir Nathaniel to come for a walk with him. The keen–witted old diplomatist guessed that there must be some motive behind the suggestion, and he at once agreed.

As soon as they were free from observation, Adam began.

"I am afraid, sir, that there is more going on in this neighbourhood than most people imagine. I was out this morning, and on the edge of the small wood, I came upon the body of a child by the roadside. At first, I thought she was dead, and while examining her, I noticed on her neck some marks that looked like those of teeth."

"Some wild dog, perhaps?" put in Sir Nathaniel.

"Possibly, sir, though I think not—but listen to the rest of my news. I glanced around, and to my surprise, I noticed something white moving among the trees. I placed the child down carefully, and followed, but I could not find any further traces. So I returned to the child and resumed my examination, and, to my delight, I discovered that she was still alive. I chafed her hands and gradually she revived, but to my disappointment she remembered nothing—except that something had crept up quietly from behind, and had gripped her round the throat. Then, apparently, she fainted."

"Gripped her round the throat! Then it cannot have been a dog."

"No, sir, that is my difficulty, and explains why I brought you out here, where we cannot possibly be overheard. You have noticed, of course, the peculiar sinuous way in which Lady Arabella moves—well, I feel certain that the white thing that I saw in the wood was the mistress of Diana’s Grove!"

"Good God, boy, be careful what you say."

"Yes, sir, I fully realise the gravity of my accusation, but I feel convinced that the marks on the child’s throat were human—and made by a woman."

Adam’s companion remained silent for some time, deep in thought.

"Adam, my boy," he said at last, "this matter appears to me to be far more serious even than you think. It forces me to break confidence with my old friend, your uncle—but, in order to spare him, I must do so. For some time now, things have been happening in this district that have been worrying him dreadfully—several people have disappeared, without leaving the slightest trace; a dead child was found by the roadside, with no visible or ascertainable cause of death—sheep and other animals have been found in the fields, bleeding from open wounds. There have been other matters—many of them apparently trivial in themselves. Some sinister influence has been at work, and I admit that I have suspected Lady Arabella—that is why I questioned you so closely about the mongoose and its strange attack upon Lady Arabella. You will think it strange that I should suspect the mistress of Diana’s Grove, a beautiful woman of aristocratic birth. Let me explain—the family seat is near my own place, Doom Tower, and at one time I knew the family well. When still a young girl, Lady Arabella wandered into a small wood near her home, and did not return. She was found unconscious and in a high fever—the doctor said that she had received a poisonous bite, and the girl being at a delicate and critical age, the result was serious—so much so that she was not expected to recover. A great London physician came down but could do nothing—indeed, he said that the girl would not survive the night. All hope had been abandoned, when, to everyone’s surprise, Lady Arabella made a sudden and startling recovery. Within a couple of days she was going about as usual! But to the horror of her people, she developed a terrible craving for cruelty, maiming and injuring birds and small animals—even killing them. This was put down to a nervous disturbance due to her age, and it was hoped that her marriage to Captain March would put this right. However, it was not a happy marriage, and eventually her husband was found shot through the head. I have always suspected suicide, though no pistol was found near the body. He may have discovered something—God knows what!—so possibly Lady Arabella may herself have killed him.