If she had not seen this, Annesley would have exclaimed against the word "obvious" for the splendid brilliant as big as a small pea which Knight put aside so carelessly. But the contrast between the modern ring with its "solitaire" diamond and the wonderful rival he gave it silenced her. She was no judge of jewellery, and had never possessed any worth having; but she knew that this second ring was a rare as well as a beautiful antique. It looked worthy, she thought, of a real princess. Even the gold was different from other gold, the little that was visible, for the square-cut stone, of pale, scintillating blue, was surrounded by a frame of tiny brilliants encrusting the rim as far as could be seen on the back of the hand when the ring was worn. "A sapphire!" Annesley exclaimed. "My favourite stone. Yet I never saw a sapphire like it before. It's wonderful--brighter than a diamond." "It is a diamond," said Knight. "A blue diamond, and considered remarkable. It's what your friend Ruthven Smith would call a 'museum piece,' if you showed it to him. But you mustn't. He'd move heaven and earth to get it! Nobody must see it but you and me. It wouldn't be safe. It's too valuable. And if you were known to have it, you'd be in danger from all the jewel thieves in Europe and America. You wouldn't like that." "No, it would be horrible!" Annesley shuddered. "But what a pity it must be hidden. Is it yours?" "It's yours at present," said Knight, "if you'll keep it to yourself, and look at it only when you and I are alone together. I can't give it to you, precisely, to have and to hold (as I shall give you myself in a few hours), because this ring is more a trust than a possession. Something may happen which will force me to ask you for it. But again, it may _not_. And, anyhow, I want you to have the ring until that time comes. I've bought a thin gold chain, and you can hang it round your neck, unless--I almost think you're inclined to refuse?" Another mystery! But the blue diamond in its scintillating frame was so alluring that Annesley could not refuse. She knew that she would have more pleasure in peeping surreptitiously at the secret blue diamond than in seeing the "obvious" white one on her finger. "I can't give it up!" she said, laughing. "But I hope it isn't one of those dreadful historic stones which have had murders committed for it, like famous jewels one reads of. I should hate anything that came from _you_ to bring bad luck." "So should I hate it. If there's any bad luck coming, I want it myself," Knight said, gravely. "I wish I hadn't spoken of bad luck to-day!" the girl remorsefully exclaimed. "But I am not afraid. Give me the ring." He gave it, and pulled from his pocket the slight gold chain on which he meant it to hang. He was leisurely threading the ring upon this when two men looked in at the door of the reading room.