(1909) The Red Room (1909) Fatal Thirteen (1909) Spies of the Kaiser (1909) Lying Lips (1910) The Unknown Tomorrow (1910) Hushed Up!: A Mystery of London (1911) The Money Spider (1911) An Eye for an Eye (1911) Revelations of the Secret Service (1911) stories The Indiscretions of a Lady's Maid, A Mystery Novel (1911) The Mystery of Nine (1912) Without Trace (1912) The Death-Doctor (1912) stories Fatal Fingers (1912) The Lost Million (1913) The Room of Secrets (1913) Mysteries (1913) stories The Hand of Allah (1914) (also as The Riddle of the Ring) Her Royal Highness; A Romance of the Chancelleries of Europe (1914) Sons of Satan (1914) The White Lie (1914) The German Spy, a Present-day story (1914) The War of the Nations (1914) with Edgar Wallace and others The Maker of Secrets (1914) The Four Faces (1914) The Sign of Silence (1915) The Devil's Spawn (1915) The Mysterious Three (1915) At the Sign of the Sword (1915) The German Spy System from Within (1915) The Mystery of the Green Ray (1915) The Double Shadow (1915) The White Glove (1915) The Man about Town (1916) Number 70, Berlin (1916) The Spy Hunter (1916) stories The Way to Win (1916) Cinders of Harley Street (1916) The Broken Thread (1916) The Place of Dragons: A Mystery (1916) Annette of the Argonne: A Story of the French Front (1916) The Scandal-Monger (1917) stories Beryl of the Biplane (1917) The Breath of Suspicion (1917) The Devil's Carnival (1917) No Greater Love (1917) Two in a Tangle (1917) Bolo, The Super-Spy, by Armand Mehjan (1918) Sant of the Secret Service: Some Revelations of Spies and Spying (1918) The Secret Life of the Ex-Tsaritza (1918) The Little Blue Goddess (1918) The Lure of Love (1918) The Yellow Ribbon (1918) The Catspaw (1918) The Sister Disciple (1918) The Stolen Statesman: Being the Story of a Hushed-Up Mystery (1918) The Doctor of Pimlico, Being the Disclosure of a Great Crime (1919) Cipher Six: A Mystery (1919) The Forbidden Word (1919) The King's Incognito (1919) No. 7 Saville Square (1920) Secrets of the Foreign Office (1920) Whither Thou Goest (1920) The Heart of a Princess: A Romance of To-Day (1920) The Intriguers (1920) The Secret Telephone (1920) The Terror of the Air (1920) The Red Widow, Or The Death-Dealers of London (1920) Mademoiselle of Monte Carlo: A Mystery of To-day (1921) The Fifth Finger: A Mystery (1921) The