Within its walls meets a little band of men and women who go through strange ceremonies and perform strange rites, and almost worship as their leader a woman who calls herself a prophetess, and who has persuaded her ignorant dupes that she is directly appointed to save them from death. The semblance of death they will know, but their souls will pass into other bodies, and in a reincarnated state they will continue to live upon the earth in greater happiness and greater health and strength and well-being than they ever knew before. The policeman on duly passes the house at night and flashes his lantern on the door, but he has no idea of the strange orgies of exaltation which take place behind the closed shutters of that charming villa residence. There are "offerings" to the prophetess, the giving up of jewellery and "adornments" for the good of the cause, and so it may be that one day the Old Bailey will see "a prophetess" in the dock again, and the spectators will look with astonishment at the men and women who enter the witness-box to tell a story that will startle the newspaper reader and make the humdrum world open its eyes and say, "Can such things be in these days of enlightenment?" In a road running off the outer circle of Regent's Park there is another house of mystery. It is walled in in front, and there is a door in the wall which is always kept locked. If you ring the bell a man-servant will open the little trap in the door and look at you keenly. You are not likely to be admitted unless you have satisfied the janitor that your visit is expected, and that your presence will be welcome to the master of the house. The master of the house is a foreigner. The name in which he dwells in the house is not his own. He is one of the most trusted agents of the great Revolutionary Party, and his guests are "comrades" who come with messages from the capitals of Europe. More than one plot which has startled the world has been arranged in that ordinary, unromantic-looking house, and its walls have from time to time sheltered men whose whereabouts certain European Governments were exceedingly anxious to discover. The Mafia! We read of this terrible Italian secret society and its murderous doings in the land of the stiletto, and we accept the printed stories with a vague suspicion that they belong to modern Italian opera rather than real life. But the emissaries of the Mafia--the Society of Vengeance--are tracking down their prey in the dull, drab streets of our own prosaic city. If you pass along the Clerkenwell Road you will come to a side street that dips down into a hollow, and this hollow, though open to the view of all who pass along the bustling London thoroughfare, is perhaps the most un-English spot in the whole of England.