I perceived how the puzzle had been worked. The box had contained an arrangement of springs, which, on being released, had expanded themselves in different directions until their mere expansion had rent the box to pieces. There were the springs, lying amid the ruin they had caused. There was something else amid that ruin besides those springs; there was a small piece of writing paper. I took it up. On the reverse side of it was written in a minute, crabbed hand: "A Present For You." What was a present for me? I looked, and, not for the first time since I had caught sight of Pugh's precious puzzle, could scarcely believe my eyes. There, poised between two upright wires, the bent ends of which held it aloft in the air, was either a piece of glass or--a crystal. The scrap of writing paper had exactly covered it. I understood what it was, when Pugh and I had tapped with the hammer, had caused the answering taps to proceed from within. Our taps caused the wires to oscillate, and in these oscillations the crystal, which they held suspended, had touched the side of the box. I looked again at the piece of paper. "A Present For You." Was _this_ the present--this crystal? I regarded it intently. "It _can't_ be a diamond." The idea was ridiculous, absurd. No man in his senses would place a diamond inside a twopenny-halfpenny puzzle box. The thing was as big as a walnut! And yet--I am a pretty good judge of precious stones--if it was not an uncut diamond it was the best imitation I had seen. I took it up. I examined it closely. The more closely I examined it, the more my wonder grew. "It _is_ a diamond!" And yet the idea was too preposterous for credence. Who would present a diamond as big as a walnut with a trumpery puzzle? Besides, all the diamonds which the world contains of that size are almost as well known as the Koh-i-noor. "If it is a diamond, it is worth--it is worth--Heaven only knows what it isn't worth if it's a diamond." I regarded it through a strong pocket lens. As I did so I could not restrain an exclamation. "The world to a China orange, it _is_ a diamond!" The words had scarcely escaped my lips than there came a tapping at the door. "Come in!" I cried, supposing it was Bob. It was not Bob, it was Pugh. Instinctively I put the lens and the crystal behind my back. At sight of me in my nightshirt Pugh began to shake his head. "What hours, Tress, what hours! Why, my dear Tress, I've breakfasted, read the papers and my letters, came all the way from my house here, and you're not up!" "Don't I look as though I were up?" "Ah, Tress! Tress!" He approached the dressing-table. His eye fell upon the ruins. "What's this?" "That's the solution to the puzzle." "Have you--have you solved it fairly, Tress?" "It has solved itself. Our handling, and tapping, and hammering must have freed the springs which the box contained, and during the night, while I slept, they have caused it to come open."