"The Big Four" is Agatha Christie's fifth novel featuring her most beloved and brilliant detective, the legendary Hercule Poirot.

In this thriller, Poirot is drawn into a sinister international conspiracy. The case begins with strange visits, cryptic clues, and the apparent death of Poirot's friend, Captain Hastings. Soon Poirot uncovers evidence of a powerful secret organization known as "The Big Four," made up of four criminal masterminds operating across the world.

The novel is more fast-paced and adventure-driven than some of Christie's other mysteries, with a global scope and a feeling of escalating danger.

"The Big Four" is presented here in its original and unabridged format.