As Tanza spoke he laid on the table a small, brass-bound, mahogany box, the patent lock of which had been forced; indeed, the whole thing appeared to have been so badly used that even the neatly made hinges were out of place. Inside were drawers and trays lined with crimson velvet, all wet and saturated as if they had been soaked in water for some time.

"You see what it is, then?" Tanza observed. "This is a jewel box. On the lid you will notice a little glass frame behind which is a sheet of paper inscribed with a list of the articles which at one time formed the contents of the box. When this casket was brought to me it was empty as you see it now; indeed, one of my men found it at low tide not very far away from the landing-stage, half imbedded in the sand. It is easy to guess whom it belongs to, seeing that the owner's monogram is on the outside, together with an address. Beyond question this once belonged to Mrs. Charlock. Mind you, I haven't heard that Mrs. Charlock was robbed of her jewels. I am simply deducing the thing from the condition this casket is in at present. In the first place, you see the casket has been forced open. Now, nobody but a thief would do that. In the second place, the casket was thrown into the sea, which is also what a thief would do. Now, who would be the most likely person to commit a crime of this sort? Who would be in a position to do so? But you know that my deductions are correct, because that rascal Bark told us who the thief was. Where the stones are is another matter. That will be something for us to find out when the mystery of the woman's death is cleared up. Meanwhile, we had better stick to the original mystery and do one thing at a time. I am bound to confess that I have slightly changed my mind, and should not be surprised to find that this lady's maid committed suicide. It is possible that Mrs. Charlock discovered her loss and traced it home to the thief. On the spur of the moment the latter goes off and drowns herself in the fountain by the sundial."

"And there," Grey said emphatically, "you are wrong. I shall be able to prove that to you before long. I, on my part, have not been altogether idle. Still, we will keep to our bargain, as you say, and each go his own way. Clever as you are, and much as I respect your opinion, I am prepared to back myself to get to the bottom of this mystery before you do. Within a week I promise not only to solve the mystery of Hortense's death, but also to produce the missing jewels."

"Ah, that's all right," Tanza exclaimed. "You are a pupil after my own heart. Do you mean to say you suspect the place where the jewels are hidden?"

"I don't suspect anything," Grey said quietly. "I know. I could put my hands upon the jewels within four-and-twenty hours."

Tanza nodded approvingly. It was characteristic of the man that he displayed no curiosity and asked no further questions. Nor had it occurred to him that Grey was speaking in a boastful spirit. He made no effort to move when Grey rose from his chair, saying he had important business on shore which might detain him to a late hour.

"All right," he said. "I presume you are on the same business still. You will be able to tell me what has happened in the morning. Well, good-night and good luck to you."

It was very late when at length Grey skirted the town and proceeded along the shore to the small block of buildings where Rent was carrying on his experiments. The buildings were in darkness. But that did not seem to trouble Grey, who threw himself down upon a bed of sea pinks and proceeded to light a cigarette. He had barely finished two before a tiny speck of light appeared in one of the windows, followed by a brilliant illumination behind the blinds as if some one was turning on the gas. As a fact, it was electric light, as Grey very well knew. He moved forward almost immediately until he stood under the shadow of the buildings. The main door was slightly open, and Grey hesitated whether he should enter or not. There was no one about, so far as he could see, though he could hear voices in the room where the light had been turned on. There was nothing to gain by timidity, so he pushed his way into the building and felt cautiously along the corridor. The door of the room where the light was stood ajar, and the intruder could see Swift standing on one side of the table and Bark opposite.

"And now you have got me here," Swift was saying, "what do you want? Why all this mystery? Why couldn't you have come to my lodgings like any other man? Instead, you drag me here as if I were a thief or something to be ashamed of."

"What else are you?" Bark said brutally. "And what else is that employer of yours, for that matter, either? Look here, my friend, I know too much about both of you to stand any nonsense. I don't want to put the cat among the pigeons, but unless I have this money by midday to-morrow somebody is going to get into trouble. That is all I have to say."