One enemy is dangerous. Four together could bring the world to its knees.

Hercule Poirot faces a threat unlike any he has encountered before when a mysterious international organization begins operating from the shadows. At its center are four powerful figures, each with a different role in a dangerous plan that reaches far beyond an ordinary crime.

As Poirot attempts to uncover their identities and motives, he finds himself drawn into a fast-moving game of deception, danger, and international intrigue. Enemies can appear without warning, identities cannot always be trusted, and every new clue seems to lead deeper into a much larger conspiracy.

The Big Four takes Hercule Poirot beyond the traditional country-house mystery and into a thrilling world of espionage, secret organizations, international power, and deadly schemes. Agatha Christie combines Poirot's legendary intelligence with a high-stakes adventure that keeps the mystery moving from one unexpected turn to the next.

For readers who enjoy classic detective fiction with suspense, conspiracies, clever investigations, and a touch of international adventure, this novel offers a fascinating side of Christie's storytelling.

Join Hercule Poirot as he takes on his most formidable opponents yet—and discover whether even his brilliant mind can defeat the Big Four.