Derby’s look questioned.  “I wonder why the Europeans make such a hit with you women,” he said.  “Why, for instance, do you find that man over there attractive?  What do you like about him?”

“Seriously?” Mrs. Davis patted her hair up the back with a little smoothing movement of satisfaction.  “I don’t know how to put it—­it is very indefinable; but a man like that has a quality—­a polish, I suppose it is, really—­that is quite irresistible.”

Derby looked rather disgusted.  “And you think that is why Nina likes them?”

“Oh, there are other reasons—­lots of them.  In the first place, Nina has a bad case of ‘allure de noblesse.’  In her case I don’t wonder!  You can’t imagine anything so heavenly as her aunt’s palace; it is every bit as fine as any of the galleries or museums.”

As though this remark added a new link to a chain of old impressions, Derby found himself asking:  “By the way—­they have a famous picture gallery out in the country somewhere, haven’t they?”

Mrs. Davis turned for information to Prince Minotti, sitting next to her; who, as he was not especially welcomed by the Romans, much affected the society of Americans, since to them, as a rule, a prince is a prince, and the name that follows of comparative unimportance.

“Torre Sansevero,” he said pompously, “is one of the finest estates we have in Italy.  In fact, the gardens are hardly less celebrated than those of the Villa d’Este, and there are a few excellent paintings.  Do you ask for any special reason?”

“No,” replied Derby casually.  “I heard they had a Raphael that was especially beautiful; I should like to see it—­that is all.”

“Do you, by chance, know the Princess Sansevero’s niece, from America, who is captivating Rome this winter?”

“Miss Randolph?  Yes.”

“Ah, then it will be easy for you to get permission to see the painting.  The gallery is not open to the public, though Cook’s, I believe, send a party out once a week, to see the gardens.”

To Derby the suspicion at once became a certainty that, in overhearing the talk between the Cook’s guide and the official, he had by accident stumbled upon something of serious importance to the Sanseveros.  He was puzzling over it when, in the smoking-room, a few moments later, he encountered Eliot Porter, an American writer who was making a study of Roman life.  At sight of Derby he called out heartily, “Hello, Jack, when did you come over?”

Derby drew up a chair beside him, and briefly sketched the object of his visit.

“Negotiating with Scorpa, I suppose?” asked Porter.

“The Sulphur King?” Derby shook his head.  “No, I don’t think I shall need him.  I have my hands on a property that promises to be what I am looking for.  The duke wants to work his mines himself and in his own way.  I am merely trying a scheme; if it turns out well, good!  If not, I shall have tested it.”