Agatha Christie's "The Big Four" is a classic detective novel featuring her renowned Belgian detective, Hercule Poirot. First published in 1927, the story revolves around Poirot's pursuit of a mysterious and powerful criminal organization known as "The Big Four." The novel is set against the backdrop of post-World War I Europe, and Poirot faces a formidable adversary as he attempts to unravel the complex web of crime orchestrated by this secretive group. The plot is marked by intricate twists, suspenseful moments, and Poirot's brilliant deductive reasoning. As with many of Christie's works, "The Big Four" showcases her mastery of the mystery genre and her ability to craft engaging and cleverly plotted stories.