The Big Four (Warbler Classics Annotated Edition‪)‬

Hercule Poirot finds himself embroiled in a world of international intrigue and espionage as he investigates a series of mysteries involving the shadowy organization known as the Big Four. These powerful international villains with worldwide reach are engaged in a variety of illicit activities including assassination, kidnapping, theft, and sabotage in their quest for global domination. As Poirot travels from London to Paris, Belgium to Italy, he must summon all his wit and cunning-and the help of his twin brother Achille-to outmaneuver the Big Four and put an end to their nefarious ambitions. 

This Warbler Classics edition includes a biographical note.