old ones.  It had not often been his fortune to be thrown in daily contact with an innocent and beautiful girl, and he ends by falling in love with you.  He knows of your love for Swain.  He has caused Swain to be forbidden the house; but he finds you still indifferent.  At last, by means of his own entreaties and your father’s, he secures your consent to become his disciple.  He knows that, if once you consent to sit with him, he will, in the end, dominate your will, also.

“But you ask for three days’ delay, and this he grants.  During every moment of those three days, he will keep you under surveillance.  Almost at once, he guesses at your plan, for you return to the house, you write a letter, and, the moment you leave your room, he enters it and sees the impression on the blotter.  He follows you into the grounds, he sees you throw the letter over the wall, and suspects that you are calling Swain to your aid.  More than that, Lester,” he added, turning to me, “he saw you in the tree, and so kept up his midnight fire-works, on the off-chance that you might be watching!”

“Yes; that explains that, too,” I agreed thoughtfully.

“When he realises that you are asking your lover’s aid,” Godfrey continued to Miss Vaughan, “a fiendish idea springs into his mind.  If Swain answers the call, if he enters the grounds, he will separate him from you once for all by causing him to be found guilty of killing your father.  He hastens back to the house, tears the leaf from the album of finger-prints and prepares the rubber gloves.  That night, he follows you when you leave the house; he overhears your talk in the arbour; and he finds that there is another reason than that of jealousy why he must act at once.  If your father is found to be insane, the will drawn up only three days before will be invalid.  Silva will lose everything—­not only you, but the fortune already within his grasp.

“He hurries to the house and tells your father of the rendezvous.  Your father rushes out and brings you back, after a bitter quarrel with Swain, which Silva has, of course, foreseen.  You come up to your room; your father flings himself into his chair again.  It is Silva who has followed you—­who has purposely made a noise in order that you might think it was Swain.  And he carries in his hand the blood-soaked handkerchief which Swain dropped when he fled from the arbour.

“Up to this point,” Godfrey went on, more slowly, “everything is clear—­every detail fits every other detail perfectly.  But, in the next step of the tragedy, one detail is uncertain—­whose hand was it drew the cord around your father’s throat?  I am inclined to think it was Mahbub’s.  If Silva had done the deed, he would probably have chosen a method less Oriental; but Mahbub, even under hypnotic suggestion, would kill only in the way to which he was accustomed—­with a noose.  Pardon me,” he added, quickly, as she shrank into her chair, “I have forgotten how repellent this must be to you.  I have spoken brutally.”