"'Do you keep your door locked at night?'

"I laughed when he spoke.

"'Certainly not,' I answered.

"'I wish you would do so,' he said very earnestly; 'will you, as a personal favour to me?'

"Jasper was in the room when he spoke. I saw a queer light flashing through his eyes, and then he bent over his book as if he had not heard.

"'As a special favour to me, keep your door locked, Helen,' said Uncle Edward.

"I made him a soothing answer, and pretended to a.s.sent. Of course I never locked my door. Then Jasper began to talk to me. He said that Uncle Edward was not only mad, but that his mania was a.s.suming a terrible form, and against me. He said that my life was in danger--he thought to frighten me--little he knew!"

Here the brave girl drew herself up, indignation sweeping over her face and filling her eyes.

"I told him I did not believe a word of what he said; I declared that Uncle Edward could not hate me--is he not the one I love best in the world? Jasper grew very angry.

"'Look here, Helen,' he said, 'I know enough to lock him up.'

"'To lock him up in a lunatic asylum?' I cried.

"'Yes,' he answered. 'I have only to get two doctors to certify to the fact of his insanity, and the deed is done. I have made up my mind to do it.'

"'You could never be so cruel,' I replied. 'Think of his grey hairs, Jasper,' I pleaded. 'He is the dearest to me in all the world; you could not take his liberty away. Do just respect his one little craze; believe me, he is not really mad. Go away if you are afraid of him; I am not.

Oh, why don't you leave us both in peace?'

"'I dare not,' he answered. 'I love you, and I am determined you shall marry me. Engage yourself to me at once, and I will do nothing to take away Uncle Edward's liberty for at least a month.'

"I struggled against this horrible wish of my cousin's, but in the end I yielded to it. I became engaged to him secretly, for he did not wish Uncle Edward to know. I knew, of course, why he wished to marry me; he had heard that I am some day to inherit my uncle's wealth. Jasper himself is a very poor man. Now, Mr. Bell, you know everything. Things get worse and worse, and at times I am almost inclined to believe that my life is in some danger. A fiend has taken possession of the uncle whose heart was so warm and loving. Ah, it is fearful! I do not believe a bitterer trial could be given to any girl--it is too awful to feel that the one she loves best in all the world has changed in his feelings towards her. It is not so much the sacrifice of my poor life I mind as the feeling that things are so bitterly altered with him. Jasper put an alternative to me last night. Either I am to marry him within a week, or I am to use my influence to induce Dr. Laurier to sign the certificate.

If I accept neither proposal, he will get down two other doctors from London for the purpose."

"What have you decided to do?" I asked.

"I will marry Jasper; yes, within a week I shall be his wife, unless something happens to show us what is the meaning of this fearful mystery, for I cannot--never, never can I deprive Uncle Edward of his liberty."

"I am glad you have confided in me," I said after a pause, "and I will do my utmost for you. When did you say that your uncle first heard the idol speak?"

"Two or three months ago now, soon after Jasper came home. Mr. Bell, is there any chance of your being able to help me?"

"I will promise to do my utmost, but just at present I can see no special light. By the way, would it not be well for you to leave The Hynde for a short time?"

"No, I am not at all afraid; I can take care of myself. It is not my dear uncle whom I fear; it is Jasper."

Soon afterwards she left me, and as it was still quite early, and the servants were not yet even up, I considered that an excellent opportunity had occurred for examining the idol.

I made my way to the gallery, and softly opening the door, stole in. The bright sunlight which was now flooding the chamber seemed to rob the grotesque old idol of half its terrors, and I made up my mind not to leave a stone unturned to discover if any foul play in connection with it could possibly be perpetrated. But the impossibility of such being the case seemed more and more evident as I went on with my search. Only a pigmy could be secreted inside the idol. There was no vulgar form of deception possible on the lines, for instance, of the ancient priests of Pompeii who conducted a speaking-tube to an idol's mouth. Siva was not even standing by the wall, thus precluding the possibility of the sounds being conducted on the plan of a whispering gallery. No--I was, against my own will, forced to the absolute conviction that the voice was an hallucination of the diseased mind of Edward Thesiger.

I was just going to abandon my investigations and return to my own room, when, more by chance than design, I knelt down for a moment at the little altar. As I was about to rise I noticed something rather odd. I listened attentively. It was certainly remarkable. As I knelt I could just hear a low, continuous hissing sound. Directly I moved away it ceased. As I tried it several times with the same invariable result, I became seriously puzzled to account for it. What devilry could be at work to produce this? Was it possible that some one was playing a trick on _me_?--and if so, by what means?

I glanced rapidly round, and as I did so a mad thought struck me. I hurried across to the fountain and put my ear close to the swan's mouth, from which a tiny jet of water was issuing. The low, scarcely audible noise that the water made as it flowed out through the swan's bill was exactly the same sound I had heard nearly twenty feet away at the altar. The enormity of the situation stunned me for a moment, then gradually, piece by piece, the plot revealed itself.

The shape of the gallery was a true oval, a geometrical ellipse, the extraordinary acoustic properties of which I knew well. This peculiarly shaped gallery contained two foci--one towards each end--and the nature of the curve of the walls was such that sound issuing from either focus was directed by reflection at various points to the other focus, and to the other focus alone. Even across an enormous distance between such would be the case. The swan's mouth was evidently at one focus; the position of a man's head as he knelt at the altar would be without the slightest doubt at the other. Could the pipe be used as a speaking-tube when the water was turned off?

I felt so excited by this extraordinary discovery that it was only with an effort that I maintained my self-control. I knew that presence of mind was absolutely necessary in order to expose this horrible scheme. I left the gallery and pa.s.sed through the conservatory. Here I found the gardener arranging some pots. I chatted to him for a few moments. He looked surprised at seeing me up at such an unusual hour.

"Can you tell me how the fountain in the gallery is turned on or off?" I asked.

"Yes, I can, sir," he replied; "the pipe runs along outside this stand, and here's the tap."

I went across and looked at it. In the leaden pipe that was fastened to the wall were two nuts, which could be turned by a small spanner, and between them was a bra.s.s cap, which fitted on to a circular outlet from the pipe.

"What is this used for?" I asked, pointing to the little outlet which was closed by the cap.

"We screw the hose on there, sir, to water the flowers."

"I see," I answered; "so when you use the hose you shut off the water from the fountain in the gallery."

"That's it, sir, and a wonderful deal of trouble it saves. Why it was never done before I can't think."

"When was it done, then?" I asked. My heart was beating fast.

"It was Mr. Bagwell's thought, sir; he had it fixed on soon after he came. He wanted to have plenty of water handy in order to water the plants he brought back from India; but, lor! sir, they'll never live through the winter, even under gla.s.s."

I waited to hear no more--the whole infernal plot was laid bare. The second tap, which shut off the water both from the fountain and the hose pipe, was, of course, quite useless, except for Bagwell's evil purpose.

I hurried straight up to Laurier's room. He was just preparing to rise.

His astonishment when I told him of my discovery was beyond words.

"Then, by shutting off the water, and applying his mouth to the place where the hose is fixed on, he could convey his voice to the swan's mouth like an ordinary speaking-tube, which, owing to the peculiar construction of the gallery, would be carried across to the other focus at the altar?" he said.

"Exactly," I replied. "And now, Dr. Laurier, you must please allow me to regulate our future plans. They're simply these. You must tell Bagwell that you absolutely refuse to sign the certificate unless Thesiger declares that he hears the voice again in your presence, and arrange that the seance takes place at nine o'clock to-night. I in the meantime shall ostensibly take my departure, and so leave the ground clear for Bagwell. He is evidently rather afraid of me. My going will throw him completely off his guard; but I shall in reality only leave the train at the next station and return here after dark. You will have to see that the conservatory door leading on to the terrace is left unlocked. I shall steal in, and, hiding myself in the conservatory, shall await Bagwell. You in the meantime will be in the gallery with Thesiger. When you hear me call out, come in at once. Our only hope is to take that wretch red-handed."

To this hastily constructed scheme Laurier instantly agreed, and at four o'clock that afternoon I took my leave, Miss Thesiger, looking white and miserable, standing on the steps to see me off. Bagwell drove me himself to the station, and bade me good-bye with a heartiness which was at least sincere.

I was back again at The Hynde at half-past eight that evening. Laurier had left the conservatory door unlocked, and, slipping in, it being now quite dark, I hid myself behind some large flowering shrubs and waited.

Presently I heard the door of the conservatory open, and in stole Bagwell. I saw him approach the pipe, turn the spanner which shut off the water from the fountain and also from the hose pipe, and then proceed to unscrew the bra.s.s cap. I waited till I saw him place his mouth to the opening and begin to speak, and then I dashed out upon him and called loudly for Laurier. Bagwell's surprise and terror at my unexpected attack absolutely bereft him of speech, and he stood gazing at me with a mixed expression of fury and fear. The next minute Laurier and Thesiger both burst in from the gallery. I still retained my hold of Bagwell. The moment I saw the sign, I went up to him, and in a few words explained the whole fraud. But it was not until I had demonstrated the trick in the oval gallery that he became convinced; then the relief on his face was marvellous.

"You leave my house at once," he said to Bagwell; "go, sir, if you do not wish to be in the hands of the police. Where is Helen? where is my child?"

He had scarcely said the words, and Bagwell was just slinking off with a white face like a whipped cur towards the door, when Helen appeared upon the scene.

"What is it?" she cried. "Is anything the matter?"

The old man strode up to her; he took her in his arms.

"It is all right, Helen," he said, "all right. I can never explain; but, take my word, it is all right. I was a fool, and worse--nay, I was mad--but I am sane now. Mr. Bell, I can never express my obligations to you. But now, will you do one thing more?"

"What is that? Be a.s.sured I will do anything in my power," I answered.