“I certainly can do so if it is worth anything.  Is that it?” I was in a fever of excitement, for I guessed what was clutched in his palm.  He held out to me the Valdez sapphire.

How it shone and sparkled like a great blue star!  I made myself a deprecating smile as I took it from him, but how dare I call it false to its face?  As well accuse the sun in heaven of being a cheap imitation.  I faltered and prevaricated feebly.  Where was my moral courage, and where was the good, honest, thumping lie that should have aided me?  “I have the best authority for recognizing this as a very good copy of a famous stone in the possession of the Bishop of Northchurch.”  His scowl grew so black that I saw he believed me, and I went on more cheerily:  “This was manufactured by Johannes Bogaerts—­I can give you his address, and you can make inquiries yourself—­by special permission of the then owner, the late Leone Montanaro.”

“Hand it back!” he interrupted (his other remarks were outrageous, but satisfactory to hear); but I waved him off.  I couldn’t give it up.  It fascinated me.  I toyed with it, I caressed it.  I made it display its different tones of color.  I must see the two stones together.  I must see it outshine its paltry rival.  It was a whimsical frenzy that seized me—­I can call it by no other name.

“Would you like to see the original?  Curiously enough, I have it here.  The bishop has left it in my charge.”

The wolfish light flamed up in Carwitchet’s eyes as I drew forth the case.  He laid the Valdez down on a sheet of paper, and I placed the other, still in its case, beside it.  In that moment they looked identical, except for the little loop of sham stones, replaced by a plain gold band in the bishop’s jewel.  Carwitchet leaned across the table eagerly, the table gave a lurch, the lamp tottered, crashed over, and we were left in semidarkness.

“Don’t stir!” Carwitchet shouted.  “The paraffin is all over the place!” He seized my sofa blanket, and flung it over the table while I stood helpless.  “There, that’s safe now.  Have you candles on the chimney-piece?  I’ve got matches.”

He looked very white and excited as he lit up.  “Might have been an awkward job with all that burning paraffin, running about,” he said quite pleasantly.  “I hope no real harm is done.”  I was lifting the rug with shaking hands.  The two stones lay as I had placed them.  No!  I nearly dropped it back again.  It was the stone in the case that had the loop with the three sham sapphires!

Carwitchet picked the other up hastily.  “So you say this is rubbish?” he asked, his eyes sparkling wickedly, and an attempt at mortification in his tone.

“Utter rubbish!” I pronounced, with truth and decision, snapping up the case and pocketing it.  “Lady Carwitchet must have known it.”

“Ah, well, it’s disappointing, isn’t it?  Good-by, we shall not meet again.”

I shook hands with him most cordially.  “Good-by, Lord Carwitchet. So glad to have met you and your mother.  It has been a source of the greatest pleasure, I assure you.”