Agatha Christie's illustrious career as a mystery novelist began in 1920 with the publication of The Mysterious Affair at Styles: A Detective Story. This marked the debut of Hercule Poirot, a character who would soon become one of the most celebrated detectives in literary history. Over the next five years, Christie published four additional novels and a collection of short stories featuring Poirot, establishing herself as a formidable presence in the genre of detective fiction.

In 1926, Christie released The Murder of Roger Ackroyd, a novel that quickly became a sensation, necessitating a second printing within weeks of its release. Its success can be attributed not only to its intricately woven plot but also to its groundbreaking narrative twist. Christie employed a daring technique, revealing the seemingly trustworthy narrator as the murderer in the story, a move that sparked both admiration and controversy among critics and readers alike.

Prior to Christie's novel, the idea of an unreliable narrator had been explored by others, but her execution of the concept was exceptionally sophisticated, drawing heightened attention. However, not everyone was impressed. Willard Huntington Wright, known for his own detective stories under the pseudonym S. S. Van Dine, criticized Christie’s approach in 1927. He dismissed the twist as "hardly a legitimate device" and argued that it undermined the integrity of Poirot’s investigative prowess. Similar sentiments were echoed by another writer, Ronald A. Knox, who in 1929 insisted that the detective genre required transparency from narrators, particularly those in the Watson-like role, who should not obscure any of their thoughts from the reader.

In contrast to these criticisms, Dorothy L. Sayers, a respected critic and crime fiction writer, staunchly defended Christie in 1928. Sayers recognized the ingenuity of Christie's plot and suggested that the objections were merely expressions of frustration from those who had been skillfully misled. Sayers argued that Christie provided all the clues necessary for an astute reader to deduce the true culprit, reinforcing the idea that it is the reader's responsibility to remain vigilant and suspicious of all characters, much like a detective.

Despite the initial controversy, The Murder of Roger Ackroyd has maintained its status as a masterpiece of detective fiction. Its innovative narrative technique continues to captivate readers, demonstrating Christie's unparalleled ability to challenge and engage her audience. Her work, especially in this novel, endures as a landmark in the genre, celebrated for its cleverness and the way it encourages readers to question their assumptions.