Going by circumstantial evidence, Diana certainly had good grounds to accuse Mrs. Vrain of committing the crime, for there were four points at least which could be proved past all doubt as incriminating her strongly in the matter.

In the first place, the female shadow on the blind seen by Lucian, showed that a woman had been in the habit of entering the house by the secret way of the cellar, and during the absence of Vrain.

Secondly, the finding of the parti-coloured ribbon in the Silent House, which had been knotted round the handle of the stiletto by Diana, and the absence of the stiletto itself from its usual place on the wall of the Berwin Manor library, proved that the weapon had been removed therefrom to London, and, presumably, used to commit the deed, seeing that otherwise there was no necessity for its presence in the Geneva Square mansion.

Thirdly, Diana had discovered that Lydia had spent the night of the murder in town; and, lastly, she also declared that the fragment of gauze found by Lucian on the dividing fence was the property of Mrs. Vrain.

This quartette of charges was recapitulated by Diana in support of her accusation of her stepmother.

"I always suspected Lydia as indirectly guilty," she declared in concluding her speech for the prosecution, "but I was not certain until now that she had actually struck the blow herself."

"But did she?" said Denzil, by no means convinced.

"I do not know what further evidence you require to prove it," retorted Diana indignantly. "She was in town on Christmas Eve; she took the stiletto from the library, and——"

"You can't prove that," interrupted Lucian decidedly. Then, seeing the look of anger on Diana's face, he hastened to apologise. "Excuse me, Miss Vrain," he said nervously. "I am not the less your friend because I combat your arguments; but in this case it is necessary to look on both sides of the question. Is it possible to prove that Mrs. Vrain removed this dagger?"

"Nobody actually saw it in her possession," replied Diana, who was more amenable to reason than the majority of her sex, "but I can prove that the stiletto, with its ribbon, remained in the library after the departure of my father. If Lydia did not take it, who else had occasion to bring it up to London?"

"Let us say Count Ferruci," suggested Denzil.

Diana pointed to the fragment of the veil lying on the table. "On the evidence of that piece of gauze," she said, "it was Lydia who entered the house. Again, you saw her shadow on the window blind."

"I saw two shadows," corrected Lucian hastily, "those of a man and a woman."

"In plain English, Mr. Denzil, those of Mrs. Vrain and Count Ferruci."

"We cannot be certain of that."

"But circumstantial evidence——"

"Is not always conclusive, Miss Vrain."

"Upon my word, sir, you seem inclined to defend this woman!"

"Miss Vrain," said Lucian seriously, "if we don't give her the benefit of every doubt the jury will, should she be tried on this charge. I admit that the evidence against this woman is strong, but it is not certain; and I argue the case looking at it from her point of view—the only view which is likely to be taken by her counsel. If Mrs. Vrain killed her husband she must have had a strong motive to do so."

"Well," said Diana impatiently, "there is the assurance money."

"I don't know if that motive is quite strong enough to justify this woman in risking her neck," responded the barrister. "As Mrs. Vrain of Berwin Manor she had an ample income, for your father seems to have left all the rents to her, and spent but little on himself; also she had an assured position, and, on the whole, a happy life. Why should she risk losing these advantages to gain more money?"

"She wanted to marry Ferruci," said Diana, driven to another point of defence. "She was almost engaged to him before she married my foolish father; she invited him to Berwin Manor against the wish of her husband, and showed plainly that she loved him sufficiently to commit a crime for his sake. With my father dead, and she in possession of £20,000, she could hope to marry this Italian."

"Can you prove that she was so reckless?"

"Yes, I can," replied Miss Vrain defiantly. "The same person who told me that Lydia was not at Berwin Manor on Christmas Eve can tell you that her behaviour with Count Ferruci was the talk of Bath."

"Who is this person?" asked Lucian, looking up.

"A friend of mine—Miss Tyler. I brought her up with me, so that you should get her information at first hand. You can see her at once," and Diana rose to ring the bell.

"One moment," interposed Lucian, before she could touch the button. "Tell me if Miss Tyler knows your reason for bringing her up."

"I have not told her directly," said Diana, with some bluntness, "but as she is no fool, I fancy she suspects. Why do you ask?"

"Because I have something to tell you which I do not wish your friend to hear, unless," added Lucian significantly, "you desire to take her into our confidence."

"No," said Diana promptly. "I do not think it is wise to take her into our confidence. She is rather—well, to put it plainly, Mr. Denzil—rather a gossip."

"H'm! As such, do you consider her evidence reliable?"

"We can pick the grains of wheat out of the chaff. No doubt she exaggerates and garbles, after the fashion of a scandal-loving woman, but her evidence is valuable, especially as showing that Lydia was not at Bath on Christmas Eve. We will tell her nothing, so she can suspect as much as she likes; if we do speak freely she will spread the gossip, and if we don't, she will invent worse facts; so in either case it doesn't matter. What is it you have to tell me?"

Lucian could scarcely forbear smiling at Diana's candidly expressed estimate of her ally's character, but, fearful of giving offence to his companion, he speedily composed his features. With much explanation and an exhibition of Miss Greeb's plan, he gave an account of his discoveries, beginning with his visit to the cellar, and ending with the important conversation with his landlady. Diana listened attentively, and when he concluded gave it as her opinion that Lydia had entered the first yard by the side passage and had climbed over the fence into the second, "as is clearly proved by the veil," she concluded decisively.

"But why should she take all that trouble, and run the risk of being seen, when it is plain that your father expected her?"

"Expected her!" cried Diana, thunderstruck. "Impossible!"

"I don't know so much about that," replied Lucian drily, "although I admit that on the face of it my assertion appears improbable. But when I met your father the second time, he was so anxious to prove, by letting me examine the house, that no one had entered it during his absence, that I am certain he was well aware the shadows I saw were those of people he knew were in the room. Now, if the woman was Mrs. Vrain, she must have been in the habit of visiting your father by the back way."

"And Ferruci also?"

"I am not sure if the male shadow was Ferruci, no more than I am certain the other was Mrs. Vrain."

"But the veil?"

Lucian shrugged his shoulders in despair. "That seems to prove it was she," he said dubiously, "but I can't explain your father's conduct in receiving her in so secretive a way. The whole thing is beyond me."

"Well, what is to be done?" said Diana, after a pause, during which they looked blankly at one another.

"I must think. My head is too confused just now with this conflicting evidence to plan any line of action. As a relief, let us examine your friend and hear what she has to say."

Diana assented, and touched the bell. Shortly, Miss Tyler appeared, ushered in by a nervous waiter, to whom it would seem she had addressed a sharp admonition on his want of deference. Immediately on entering she pounced down on Miss Vrain like a hawk on a dove, pecked her on both cheeks, addressed her as "my dearest Di," and finally permitted herself, with downcast eyes and a modest demeanour, to be introduced to Lucian.

It might be inferred from the foregoing description that Miss Tyler was a young and ardent damsel in her teens; whereas she was considerably nearer forty than thirty, and possessed an uncomely aspect unpleasing to male eyes. Her own were of a cold grey, her lips were thin, her waist pinched in, and—as the natural consequence of tight lacing—her nose was red. Her scanty hair was drawn off her high forehead very tightly, and screwed into a cast-iron knob at the nape of her long neck; and she smiled occasionally in an acid manner, with many teeth. She wore a plainly-made green dress, with a toby frill; and a large silver cross dangled on her flat bosom. Altogether, she was about as venomous a specimen of an unappropriated blessing as can well be imagined.

"Bella," said Miss Vrain to this unattractive female, "for certain reasons, which I may tell you hereafter, Mr. Denzil wishes to know if Mrs. Vrain was at Berwin Manor on Christmas Eve."

"Of course she was not, dearest Di," said Bella, drooping her elderly head on one scraggy shoulder, with an acid smile. "Didn't I tell you so? I was asked by Lydia—alas! I wish I could say my dearest Lydia—to spend Christmas at Berwin Manor. She invited me for my singing and playing, you know: and as we all have to make ourselves agreeable, I came to see her. On the day before Christmas she received a letter by the early post which seemed to upset her a great deal, and told me she would have to run up to town on business. She did, and stayed all night, and came down next morning to keep Christmas. I thought it very strange."

"What was her business in town, Miss Tyler?" asked Lucian.

"Oh, she didn't tell me," said Bella, tossing her head, "at least not directly, but I gathered from what she said that something was wrong with poor dear Mr. Clyne—her father, you know, dearest Di."

"Was the letter from him?"

"Oh, I couldn't say that, Mr. Denzil, as I don't know, and I never speak by hearsay. So much mischief is done in the world by people repeating idle tales of which they are not sure."

"Was Count Ferruci at Berwin Manor at the time?"

"Oh, dear me, no, Di! I told you that he was up in London the whole of Christmas week. I only hope," added Miss Tyler, with a venomous smile, "that Lydia did not go up to meet him."

"Why should she?" demanded Lucian bluntly.

"Oh, I'm not blind!" cried Bella, shrilly laughing. "No, indeed. The Count—a most amiable man—was very attentive to me at one time; and Lydia—a married woman—I regret to say, did not like him being so. I am indeed sorry to repeat scandal, Mr. Denzil, but the way in which Mrs. Vrain behaved towards me and carried on with the Count was not creditable. I am a gentlewoman, Mr. Denzil, and a churchwoman, and as such cannot countenance such conduct as his."

"You infer, then, that Mrs. Vrain was in love with the Italian?"

"I shouldn't be at all surprised to hear it," cried Bella again. "But he did not care for her! Oh, dear, no! It is my belief, Mr. Denzil, that Mrs. Vrain knows more about the death of her husband than she chooses to admit. Oh, I've read all the papers; I know all about the death."

"Miss Tyler!" said Lucian, alarmed.

"Bella!" cried Miss Vrain. "I——"

"Oh, I'm not blind, dearest," interrupted Bella, speaking very fast. "I know you ask me these questions to find out if Lydia killed her husband. Well, she did!"

"How do you know, Miss Tyler?"

"Because I'm sure of it, Mr. Denzil. Wasn't Mr. Vrain stabbed with a dagger? Very well, then. There was a dagger hanging in the library of the Manor, and I saw it there four days before Christmas. When I looked for it on Christmas Day it was gone."

"Gone! Who took it?"

"Mrs. Vrain!"

"Are you sure?"

"Yes, I am!" snapped Miss Tyler. "I didn't see her take it, but it was there before she went, and it wasn't there on Christmas Day. If Lydia did not take it, who did?"

"Count Ferruci, perhaps."

"He wasn't there! No!" cried Bella, raising her head, "I'm sure Mrs. Vrain stole it and killed her husband, and I don't care who hears me say so!"

Diana and Lucian looked at one another in silence.