In front of me I saw Craig grasping Mrs. Popper’s wrists as in a vise.  She was glaring at him like a tigress.

“Do you suppose for a moment that that toy is going to convince the world that Henry Vandam has been deceived and that the spirit which visited him was a fraud?  Is that why you have lured me here under false pretences, to play on my feelings, to insult me, to take advantage of a lone, defenceless woman, surrounded by hostile men?  Shame on you,” she added contemptuously.  “You call yourself a gentleman, but I call you a coward.”

Kennedy, always calm and collected, ignored the tirade.  His voice was as cold as steel as he said:  “It would do little good, Mrs. Popper, to destroy this one link in the chain I have forged.  The other links are too heavy for you.  Don’t forget the evidence of the ink.  It was your ink.  Don’t forget that Henry Vandam will not any longer conceal that he has altered his will in favour of you.  To-night he goes from here to his lawyer’s to draw up a new will altogether.  Don’t forget that you have caused the Vandams separately to have the prescription filled, and that you are now caught in the act of a double murder.  Don’t forget that you had access to the Vandam mansion, that you substituted the deadly for the harmless capsules.  Don’t forget that your rappings announced the death of one of your victims and urged the other, a cruelly wronged and credulous old man, to leave millions to you who had deceived and would have killed him.

“No, the record of the ghost on the seismograph was not Mr. Farrington’s, as I implied at the moment when you so kindly furnished this additional proof of your guilt by trying to destroy the evidence.  The ghost was you, Mrs. Popper, and you are at liberty to examine the markings as minutely as you please, but you must not destroy them.  You are an astute criminal, Mrs. Popper, but to-night you are under arrest for the murder of Mary Vandam and the attempted murder of Henry Vandam.”

VI.  The Diamond Maker

“I’ve called, Professor Kennedy, to see if we can retain you in a case which I am sure will tax even your resources.  Heaven knows it has taxed ours.”

The visitor was a large, well-built man.  He placed his hat on the table and, without taking off his gloves, sat down in an easy chair which he completely filled.

“Andrews is my name—­third vice-president of the Great Eastern Life Insurance Company.  I am the nominal head of the company’s private detective force, and though I have some pretty clever fellows on my staff we’ve got a case that, so far, none of us has been able to unravel.  I’d like to consult you about it.”

Kennedy expressed his entire willingness to be consulted, and after the usual formalities were over, Mr. Andrews proceeded.

“I suppose you are aware that the large insurance companies maintain quite elaborate detective forces and follow very keenly such of the cases of their policy-holders as look at all suspicious.  This case which I wish to put in your hands is that of Mr. Solomon Morowitch, a wealthy Maiden Lane jeweller.  I suppose you have read something in the papers about his sudden death and the strange robbery of his safe?”