"Very good; very, very good," de Grandin nodded vigorously. "Now attend me, if you please:
"When Monsieur Kinnan told me of the hammer which broke his window last night I decided the road by which to trace this bodiless burglar was mapped out on that hammer's handle. Pourquoi? Because this hand which scares sick ladies to death and breaks windowpanes is one of three things. First"—he ticked off on his fingers—"it may be some mechanical device. In that case I shall find no traces. But it may be the ghost of someone who once lived, in which case, again, it is one of two things: a ghost hand, per se, or the reanimated flesh of one who is dead. Or, perchance, it is the hand of someone who can render the rest of him invisible.
"Now, then, if it is a ghost hand, either true ghost or living-dead flesh, it is like other hands, it has ridges and valleys and loops and whorls, which can be traced and recognized by fingerprint experts. Or, if a man can, by some process unknown to me, make all of him, save his hand, invisible, why, then, his hand, too, must leave finger marks. Hein?
"'Now,' Jules de Grandin asked Jules de Grandin, 'is it not highly probable that one who steal jewels and bonds and the cup of Monsieur le Marquis de Lafayette, has stolen before, perchance been apprehended, and fingerprinted?'
"'Parbleu! It is even as you say,' Jules de Grandin answer Jules de Grandin.
"Thereupon I take that hammer from Monsieur Kinnan's house and go with it to New York. I see the Commissioner of Police. 'Monsieur le Prefet,' I say to him, 'I am Jules de Grandin. Do you know me?'
"'Morbleu, but I do,' reply that so excellent gentleman. 'Who but a fool has not heard of Jules de Grandin?'"
He paused a moment, easting a pregnant glance at Richards, then continued:
"'Monsieur le Prefet' I reply, 'I would that you permit your identification experts to examine this hammer and tell me, of their kindness, whose fingerprints appear thereon.'
"Bien, the order was given, and in good time come the report that the hammer handle is autographed with the fingerprints of one Katherine O’Brien, otherwise known to the police as Catherine Levoy, and also known as Catherine Dunstan.
"The police of New York have a dossier for this lady which would do credit to the Paris Sûreté. They tell me she was in turn a shoplifter, a decoy-woman for some badger game gentlemen, a forger and the partner of one Professor Mysterio, a theatrical hypnotist. Indeed, they tell me, she was married to this professor à l’Italienne, and with him she traveled the country, sometimes giving exhibitions, sometimes indulging in crime, such as, for instance, burglary and pocket-picking.
"Now, about a year ago, while she and the professor are exhibiting themselves at Coney Island, this lady died. Her partner gave her a most remarkable funeral; but the ceremonies were marred by one untoward incident—while her body lay in the undertaker’s mortuary some thief did climb in the window and remove one of her hands. In the dead of night he severed from the beautiful body of that wicked woman the hand which had often extracted property from other people’s pockets, and made off with it; nor could all the policemen’s efforts find out who did so ghoulish a deed.
"Meantime, the professor who was this woman’s theatrical partner has retired from the stage and lives in New Jersey on the fortune he has amassed.
