In Chapter V of “The Mysterious Affair at Styles,” titled “It Isn’t Strychnine, Is It?”, intrigue deepens as Hercule Poirot and the narrator explore the remnants of the previous night’s mysterious events. They discover a note in Mrs. Inglethorp’s handwriting, stirring speculation about her mental state and possible suicide. However, Poirot’s attention is caught by other clues, leading them to scrutinize the household’s coffee cups, only to find no evidence of strychnine poisoning.

Poirot’s meticulous methods reveal a puzzling lack of strychnine and lead to a complicated web of family tensions and secrets. Despite the ongoing investigation, the family attempts to maintain a semblance of normalcy. Poirot, undeterred by the lack of poison evidence, remains focused on the coffee cups as a vital clue. The detective’s inquiry into Mrs. Inglethorp’s activities the day before her death uncovers a hurriedly drafted will and a contentious relationship with Alfred Inglethorp, raising suspicions about motives within the household.

The narrative further thickens with the introduction of a hastily made will, potential motives from various family members, and a surprising admission about Mrs. Inglethorp’s knowledge of her marital status’s effect on her will. Hercule Poirot’s ingenious deduction connects seemingly minor details, demonstrating his unparalleled analytical skills. Amidst conflicting loyalties and hidden agendas, Poirot’s pursuit of truth showcases his methodical approach to unraveling complex mysteries. His attention to minute details and unwavering determination illuminate the intricate dynamics at play, culminating in a compelling exploration of deceit and intrigue within the Inglethorp household.