Belgian detective Hercule Poirot decides to conclude his professional career by solving twelve final cases, each meticulously chosen to mirror the mythological labours of Hercules. Poirot seeks to impose order and classical symmetry upon his remaining investigations, viewing these final tasks as a symbolic retirement. He faces a variety of criminal adversaries and complex puzzles, often navigating social circles that test his patience and intellect. The narrative framework utilizes a series of interconnected short stories, each functioning as a distinct puzzle while contributing to the overarching theme of Poirot's departure from active duty.

This collection is widely regarded as a clever experiment in structure that highlights Christie's ability to blend classical allusion with the traditional detective format. Readers often note that while some connections to the original myths are more forced than others, the conceit provides a satisfying framework for Poirot's final bow. The stories are frequently praised for their concise pacing and the characteristic charm of the protagonist as he navigates his swan song. It remains a staple for fans of the series who appreciate the meta-fictional layer Christie adds to the detective genre.