We hold that he is a gentleman, or at least an educated man, possibly a medical man, a medical student, or a _dilettante_ in toxicology. A common assassin would have decoyed his victim into a house and murdered her in a more brutal manner, by cutting her throat or battering her head with a poker, but this strange assassin, secure in the possession of a weapon more deadly, engages his unhappy victim in confidential talk, and whilst embracing her causes her death in a sure manner. It is a Judas-like crime, the kiss of friendship and the heart of treachery, therefore we say the criminal who possesses these refined and fiendish instincts must be an educated man, and also one who must have no little knowledge of poisons to employ the subtle drug he did. The nature of the poison cannot be discovered, as the simple scratch corrupted the blood and there are no local signs to tell what kind was employed. As to the motive of the crime, it may have been love, it may have been jealousy, perhaps robbery; as no money or jewellery were found on the body, and there was a mark on the neck as though a chain had been roughly wrenched off. What we have set forth is mere conjecture, for the assassin may be a woman, but we think this improbable. No woman would have the nerve to commit such a crime in the open street--true the assassin, was favoured by the fog which hid his or her crime behind an impenetrable veil, but still the risk was enormous. But be the assassin man or woman there is no doubt we have in our midst a human fiend who, possessed of a deadly weapon, namely, a poisoned dagger, can commit crimes with impunity? A slight scratch given in a certain portion of the body and the victim is doomed. Who is to point out the assassin, unless he or she is actually seen committing the crime. We have not yet heard the end of the Piccadilly Puzzle, but it will take all the acumen and ingenuity of the London detective to trace this secret assassin, and our only dread is lest some other victim may fall before his or her terrible weapon. But though the assassin of this unknown woman may escape the consequences of this crime, sooner or later he will thirst again for blood, and the second time he may not be so fortunate. Let him remember Tho' the mills of God grind slowly, They grind exceeding small. CHAPTER III. DOWKER--DETECTIVE.