Zoraida: A Romance of the Harem and the Great Sahara

Devil's Dice: Espionage, Intrigue, and Deception in Early 20th-Century Europe

The Minister of Evil: The Secret History of Rasputin's Betrayal of Russia

The Great War in England in 1897 & The Invasion of 1910

Tracked by Wireless: Enriched edition. A Thrilling Tale of Espionage and Wireless Technology in Early 20th Century Europe

The Day of Temptation: Intrigue and Espionage in Pre-World War I Europe

The Secrets of Potsdam: A Startling Exposure of the Inner Life of the Courts of the Kaiser and Crown-Prince

The Lost Million: Espionage, Conspiracy, and Intrigue in Early 20th-Century Europe

The Stolen Statesman: Being the Story of a Hushed Up Mystery

The Bomb-Makers

The Great War in England in 1897: Invasion, Espionage, and Fear: A Historical Thriller

The Red Room: Intrigue and Espionage in a Europe on the Brink of War

The Invasion

The Golden Face: A Great 'Crook' Romance

The Bond of Black

The Invasion: Espionage and Intrigue in Early 20th Century England

The Price of Power: Being Chapters from the Secret History of the Imperial Court of Russia

Britain's Deadly Peril: Espionage, Conspiracy, and Danger in Early 20th Century Britain

The White Lie: Betrayal and Deception: A Tale of Espionage and Intrigue

The Collected Spy Thrillers