For the truth does not lie in the open road, and to take the narrow winding way that leads to it, one must be armed with two things--the word that will carry you past the vigilant sentinels and the knowledge that will insure your safe return. I have said so much that the reader who wishes to accompany me in these journeys in search of the mysterious side of London life may know over what ground we shall have to travel But I should like to say one word more. We shall not need police escort or protection. My obligation to the police is great for many kindly services rendered, and I have the sincerest admiration for the patience and the energy with which they guard the capital's wealth and the lives of its citizens, but I have never asked for their assistance in my journeyings into dark places. The police are known, and in their presence the tongue of the local gossip is tied, and the intentions of the person accompanying them are suspected. Wherever I have gone it has always been alone or with someone whom the inhabitants of the area--whether honest or criminal, toilers or idlers, decent folk or outcasts--have always regarded with a friendly eye. Often a journey has been made alone. It has been made by day and by night, and though there have been times when I have been glad to see the beaten track and the lights and the traffic again, I have never received either insult or injury. And I have Been in spots that are officially recognized as the most dangerous in London. I do not make this statement in any boastful spirit, for there is no credit due to me for escaping the dangers of the dark alley and the underground cellar, the peril of the secret haunt of the foreign desperadoes, the attack of the prowling hooligan, and the wrath of the criminal surprised in the active practice of his profession. I have gone with a passport which has enabled me to secure, if not the absolute confidence of the victims of my curiosity, at least their abstention from active resistance to my intrusion. But the mysteries of London do not confine themselves to any one quarter or to any one class. They are to be found in the broad terraces of the West as often as in the narrow alleys of the East. In the criminal courts it is not always the prisoner in the dock who has the ghastliest skeleton in his cupboard. When the police van passes the aristocratic equipage with the coronetted panels, the elegantly dressed occupant of the latter may have the haunting terror of to-morrow in her heart, while the outcast on her road to Holloway is by comparison free from care. There are mysteries in the lordly mansions of the West that make wealth a mockery and rank a disaster. The jealous guarding of the family secret is a task that embitters the lives of brave men and fair women who bear the name that discovery would stain and besmirch.