To illustrate the crucial importance of understanding the criminal mind, Christie places Poirot’s belief in psychological insight in direct conflict with Giraud’s focus on physical evidence. Giraud works like a “human foxhound” and searches for tangible clues like footprints while Poirot says real detection begins “from within.” Giraud misreads the evidence he gathers and arrests an innocent man while Poirot eventually solves the case, which highlights how a detective needs to grasp motive and emotion and understand the logic behind deception.

Giraud appears early in the book as a modern detective who trusts his own rigorous fieldwork. He mocks Poirot’s quieter style when he says that “methods are very different now” (51). Giraud thoroughly examines the crime scene, crawling on the ground, measuring footprints, and collecting fragments. He proudly presents a cigarette stub and a South American match as firm proof of the killers’ origins, yet he concentrates so fully on these objects that he never realizes that someone planted them there. He accepts every clue at face value, and this ill-founded certainty leaves him open to any trick a resourceful criminal sets.

In contrast, Poirot treats physical evidence with caution and sees how easily someone can use objects to distract investigators. He identifies the cigarette and matches that Giraud values so highly as items “[d]eliberately planted there for Giraud or one of his tribe to find” (106). Poirot turns instead to the small gaps in people’s stories. One of his most important discoveries comes from the fast wristwatch smashed in Mrs. Renauld’s room. Others dismiss it, but Poirot sees that someone moved the hands forward two hours to distort the timeline. This detail, once he considers the intention behind it, unravels the staged scene. Poirot’s methods are founded on his view that a detective must look beyond physical traces.

Poirot eventually reaches the truth by looking beyond the crime scene and examining the older Beroldy case. His research reveal that Renauld and Madame Daubreuil are living under new identities and that blackmail and fear have shaped events for years. Giraud, who locks his attention on what he can gather from the ground, never sees these connections. His approach confines him to the immediate moment and leads him to arrest the wrong suspect based on a flawed reading of scattered clues. Poirot’s method prevails and shows how psychological insight guides the investigation to its resolution. Giraud’s failures offer a cautionary tale about going through life fixated on the “what” of surface-level details instead of looking for the deeper “why” that guides people’s actions.