The Great Impersonation (1920) is a gripping espionage thriller by E. Phillips Oppenheim. Set on the eve of World War I, the novel revolves around English aristocrat Sir Everard Dominey and his mysterious return to society after years in Africa. Suspicions arise when it appears he might actually be a German spy, Baron von Ragastein, sent to infiltrate British high society. The plot twists around questions of identity, deception, and loyalty, as characters try to uncover the truth. Oppenheim builds suspense through a mix of political intrigue and personal drama, with a richly atmospheric Edwardian setting. The psychological tension keeps readers guessing until the end. Blending romance, espionage, and mystery, The Great Impersonation remains a standout in early 20th-century spy fiction.