The millionaire connoisseur consulted his watch.  “Lith will be at the museum until six, at least.  Yes, we can catch him there.  I have a dinner engagement at seven myself.  I can give you half an hour of the time before then.  If you’re ready, just jump into the car, both of you.”

The museum to which he referred was a handsome white marble building, in Renaissance, fronting on a side street just off Fifth Avenue and in the rear of the famous Spencer house, itself one of the show places of that wonderful thoroughfare.  Spencer had built the museum at great cost simply to house those treasures which were too dear to him to entrust to a public institution.  It was in the shape of a rectangle and planned with special care as to the lighting.

Dr. Lith, a rather stout, mild-eyed German savant, plunged directly into the middle of things as soon as we had been introduced.  “It is a most remarkable affair, gentlemen,” he began, placing for us chairs that must have been hundreds of years old.  “At first it was only those objects in the museum, that were green that were touched, like the collection of famous and historic French emeralds.  But soon we found it was other things, too, that were missing—­old Roman coins of gold, a collection of watches, and I know not what else until we have gone over the—­”

“Where is Miss White?” interrupted Spencer, who had been listening somewhat impatiently.

“In the library, sir.  Shall I call her?”

“No, I will go myself.  I want her to tell her experience to Professor Kennedy exactly as she told it to me.  Explain while I am gone how impossible it would be for a visitor to do one, to say nothing of all, of the acts of vandalism we have discovered.”

VII

THE GREEN CURSE

The American Medici disappeared into his main library, where Miss White was making a minute examination to determine what damage had been done in the realm over which she presided.

“Apparently every book with a green binding has been mutilated in some way,” resumed Dr. Lith, “but that was only the beginning.  Others have suffered, too, and some are even gone.  It is impossible that any visitor could have done it.  Only a few personal friends of Mr. Spencer are ever admitted here, and they are never alone.  No, it is weird, mysterious.”

Just then Spencer returned with Miss White.  She was an extremely attractive girl, slight of figure, but with an air about her that all the imported gowns in New York could not have conferred.  They were engaged in animated conversation, so much in contrast with the bored air with which Spencer had listened to Dr. Lith that even I noticed that the connoisseur was completely obliterated in the man, whose love of beauty was by no means confined to the inanimate.  I wondered if it was merely his interest in her story that impelled Spencer.  The more I watched the girl the more I was convinced that she knew that she was interesting to the millionaire.