“Yes, I leave early in the morning.”

“Take my advice”—­his glance was sinister—­“and stay away.”

Derby smiled frankly.  “May I ask why?”

“Because your process will not work.”

“That might be taken in two ways,” Derby rejoined:  “either that you believe my patents useless, or else that some means will be taken to prevent my trying them.  I rather wonder—­after our conversation on the subject—­if you intend a threat?” He spoke without stress of feeling, quite simply, in fact.

The duke’s unctuous smile was not wholly pleasant to see.  “That is for you to decide.  To-morrow morning you intend to go.  That is not far off; but you have until then to reconsider your refusal to sell me your patents.  I made you a fair offer, which I should in your place accept.  However, if you go to Sicily”—­he spread out his hands with a shrug—­“I shall have warned you, and whatever comes will be off my conscience.”

For answer Derby spoke quietly, but with clear, level distinctness.  “I go to-morrow to Vencata, to work a piece of land which is the property of the Prince and Princess Sansevero.  As their representative, I am vested with every legal right to apply my invention to the mine known as the ‘Little Devil.’  And I may add”—­he put it casually—­“that back of me is the full strength and protection of the United States Government.”  He looked straight into the small rat-like eyes nearly a foot below his own.  Then with a smile he bowed to the Contessa Zoya and went in search of the Princess Sansevero, to say good-by.

He found her in the adjoining room, absorbed in the music; and luckily there was an empty chair beside her, into which he quietly dropped.  She smiled her welcome as he sat down beside her, but she had accepted her young countryman into too good a friendship to make either of them feel the need of rushing into speech.  After a little she turned to him; even then her sentence seemed to complete a conversation interrupted rather than a new one begun, “Above all, do not forget to present Sandro’s letter to the Archbishop!  I know you will be drawn to him.  His Eminence is one of those rare persons who have not waited to die to become angels.”  She smiled.  “I am sure you will be safe under his protection.”

“I wish you would tell me, Princess, why there is so much talk of protection—­it sounds as though I were going to explore the interior of Africa!  I shall be, at most, twenty-four hours away from Rome.”

“There is no knowing what you are going to explore”—­a shade of anxiety had come into her face.  “The Mafia is there, the people are ignorant, and the lava wastes are as desolate and wild as any spot in Africa.  I hope there will be no danger, but it is well to take precautions before going into such a country.  You will promise me won’t you?—­to follow the directions of his Eminence.”  Unconsciously she put her hand against her heart.

Derby gave his promise easily, and she held out her hand.  He kissed it after the European custom; and as he did so he felt her fingers tighten over his, as she whispered with a little underlying emotional vibration, “God bless you, my dear boy!—­and a safe return.”