- *The Fatal Bequest* (1892)
- *For Her Sake* (1893)
- *Her Dilemma* (1894)
- *A Family Secret* (1895)
- *Her Mother's Sin* (1896)
- *Her Husband's Secret* (1897)
- *A Romance of Monte Carlo* (1898)
- *A Ward of the King* (1899)
- *Her Second Self* (1900)
- *A Man and a Woman* (1901)
- *The Shadow on the Stair* (1902)
- *Her Sister's Rival* (1903)
- *The Mystery of Mr. Bernard Brown* (1904)
- *The Blue Diamond* (1905)
- *The Stolen Statesman* (1906)
- *The Red House Mystery* (1907)
- *The Green Man's Folly* (1908)
- *The Lost Millionaire* (1909)
- *The Jewel House Mystery* (1910)
- *The Mysterious Mr. Jason* (1911)
- *The Secret of the Tower* (1912)
- *The Missing Heiress* (1913)
- *The Phantom Signal* (1914)
- *The Shadow of a Crime* (1915)
- *The Secret Five* (1916)
- *The Clue of the Dead Hand* (1917)
- *The Mystery of the Hasty Arrow* (1918)
- *The Riddle of the Red Rose* (1919)
- *The Tragedy of the Golden Salamander* (1920)
- *The Sign of the Seven Stars* (1921)
- *The Crime at Golden Square* (1922)
- *The Mystery of the Secret Service* (1923)
- *The Vanishing Man* (1924)
- *The Shadow of the Vulture* (1925)
- *The House of Whispers* (1926)
- *The Silent Messenger* (1927)
- *The Mystery of the Invisible Hand* (1928)
- *The Riddle of the Golden Key* (1929)
- *The Case of the Missing Bride* (1930)
- *The Affair of the Black Box* (1931)
- *The Clue of the Red Spider* (1932)
- *The Trail of the Scarlet Moth* (1933)
- *The Man from Nowhere* (1934)
- *The Shadow of Evil* (1935)
- *The Mystery of the Purple Scarab* (1936)
- *The Crime in the Green Room* (1937)
- *The Clue of the Silver Arrow* (1938)
- *The Secret of the Jade Buddha* (1939)
Short Stories:
- "The Missing Clue"
- "The Stolen Statesman"
- "The Mysterious Message"
- "The Shadowed Room"
- "The Dead Hand"
- "The Phantom Signal"
- "The Riddle of the Red Rose"
- "The Hasty Arrow"
- "The Golden Salamander"
- "The House of Whispers"
- "The Invisible Hand"
- "The Golden Key"