"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 glass." 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.