Spies of the Kaiser: Plotting the Downfall of England
The Place of Dragons: A Mystery
The Veiled Man
The Mystery of the Green Ray
The Great White Queen: A Tale of Treasure and Treason
The Seven Secrets
Whither Thou Goest
The Count's Chauffeur
Whatsoever a Man Soweth
The Temptress
Her Royal Highness: A Romance of the Chancelleries of Europe
The Lost Million
The Red Room
The Mysterious Mr. Miller
The Pauper of Park Lane
The Great God Gold
In White Raiment
Devil's Dice
An Eye for an Eye
Hushed Up! A Mystery of London
The Broken Thread
The House of Whispers
If Sinners Entice Thee
As We Forgive Them
Behind the Throne
Guilty Bonds
The Mysterious Three
The Wiles of the Wicked
The Bond of Black
The Sign of the Stranger
The Bomb-Makers
The Four Faces: A Mystery
The Hunchback of Westminster
Mademoiselle of Monte Carlo
The Stolen Statesman: Being the Story of a Hushed Up Mystery