“Yes, this is the great Agra treasure. Half of it is yours and half is Thaddeus Sholto’s. You will have a couple of hundred thousand each. Think of that! An annuity of ten thousand pounds. There will be few richer young ladies in England. Is it not glorious?”

I think I must have been rather over-acting my delight, and that she detected a hollow ring in my congratulations, for I saw her eyebrows rise a little, and she glanced at me curiously.

“If I have it,” said she, “I owe it to you.”

“No, no,” I answered, “not to me but to my friend Sherlock Holmes. With all the will in the world, I could never have followed up a clue which has taxed even his analytical genius. As it was, we very nearly lost it at the last moment.”

“Pray sit down and tell me all about it, Dr. Watson,” said she.

I narrated briefly what had occurred since I had seen her last. Holmes’s new method of search, the discovery of the Aurora, the appearance of Athelney Jones, our expedition in the evening, and the wild chase down the Thames. She listened with parted lips and shining eyes to my recital of our adventures. When I spoke of the dart which had so narrowly missed us, she turned so white that I feared that she was about to faint.

“It is nothing,” she said as I hastened to pour her out some water. “I am all right again. It was a shock to me to hear that I had placed my friends in such horrible peril.”

“That is all over,” I answered. “It was nothing. I will tell you no more gloomy details. Let us turn to something brighter. There is the treasure. What could be brighter than that? I got leave to bring it with me, thinking that it would interest you to be the first to see it.”

“It would be of the greatest interest to me,” she said. There was no eagerness in her voice, however. It had struck her, doubtless, that it might seem ungracious upon her part to be indifferent to a prize which had cost so much to win.

“What a pretty box!” she said, stooping over it. “This is Indian work, I suppose?”

“Yes; it is Benares metal-work.”

“And so heavy!” she exclaimed, trying to raise it. “The box alone must be of some value. Where is the key?”

“Small threw it into the Thames,” I answered. “I must borrow Mrs. Forrester’s poker.”

There was in the front a thick and broad hasp, wrought in the image of a sitting Buddha. Under this I thrust the end of the poker and twisted it outward as a lever. The hasp sprang open with a loud snap. With trembling fingers I flung back the lid. We both stood gazing in astonishment. The box was empty!

No wonder that it was heavy. The ironwork was two-thirds of an inch thick all round. It was massive, well made, and solid, like a chest constructed to carry things of great price, but not one shred or crumb of metal or jewellery lay within it. It was absolutely and completely empty.

“The treasure is lost,” said Miss Morstan calmly.

As I listened to the words and realized what they meant, a great shadow seemed to pass from my soul. I did not know how this Agra treasure had weighed me down until now that it was finally removed. It was selfish, no doubt, disloyal, wrong, but I could realize nothing save that the golden barrier was gone from between us.

“Thank God!” I ejaculated from my very heart.

She looked at me with a quick, questioning smile.

“Why do you say that?” she asked.

“Because you are within my reach again,” I said, taking her hand. She did not withdraw it. “Because I love you, Mary, as truly as ever a man loved a woman. Because this treasure, these riches, sealed my lips. Now that they are gone I can tell you how I love you. That is why I said, ‘Thank God.’ ”

“Then I say ‘Thank God,’ too,” she whispered as I drew her to my side.