by ‘suggestion,’ but I would have undertaken to produce the same effect on almost any woman.  The key to the Big Bow Mystery is feminine psychology.  The only uncertain link in the chain was, Would Mrs. Drabdump rush across to get me to break open the door?  Women always rush for a man.  I was well-nigh the nearest, and certainly the most authoritative man in the street, and I took it for granted she would.”

“But suppose she hadn’t?” the Home Secretary could not help asking.

“Then the murder wouldn’t have happened, that’s all.  In due course Arthur Constant would have awoke, or somebody else breaking open the door would have found him sleeping; no harm done, nobody any the wiser.  I could hardly sleep myself that night.  The thought of the extraordinary crime I was about to commit—­a burning curiosity to know whether Wimp would detect the modus operandi—­the prospect of sharing the feelings of murderers with whom I had been in contact all my life without being in touch with the terrible joys of their inner life—­the fear lest I should be too fast asleep to hear Mrs. Drabdump’s knock—­these things agitated me and disturbed my rest.  I lay tossing on my bed, planning every detail of poor Constant’s end.  The hours dragged slowly and wretchedly on towards the misty dawn.  I was racked with suspense.  Was I to be disappointed after all?  At last the welcome sound came—­the rat-tat-tat of murder.  The echoes of that knock are yet in my ear.  ’Come over and kill him!’ I put my night-capped head out of the window and told her to wait for me.  I dressed hurriedly, took my razor, and went across to 11 Glover Street.  As I broke open the door of the bedroom in which Arthur Constant lay sleeping, his head resting on his hands, I cried, ‘My God!’ as if I saw some awful vision.  A mist as of blood swam before Mrs. Drabdump’s eyes.  She cowered back, for an instant (I divined rather than saw the action) she shut off the dreaded sight with her hands.  In that instant I had made my cut—­precisely, scientifically—­made so deep a cut and drawn out the weapon so sharply that there was scarce a drop of blood on it; then there came from the throat a jet of blood which Mrs. Drabdump, conscious only of the horrid gash, saw but vaguely.  I covered up the face quickly with a handkerchief to hide any convulsive distortion.  But as the medical evidence (in this detail accurate) testified, death was instantaneous.  I pocketed the razor and the empty sulfonal phial.  With a woman like Mrs. Drabdump to watch me, I could do anything I pleased.  I got her to draw my attention to the fact that both the windows were fastened.  Some fool, by the by, thought there was a discrepancy in the evidence because the police found only one window fastened, forgetting that, in my innocence I took care not to refasten the window I had opened to call for aid.  Naturally I did not call for aid before a considerable time had elapsed.  There was Mrs. Drabdump to quiet, and the excuse of making notes—­as