In The Third Floor Flat, the setting of a London apartment building creates a sense of closeness and suspense, as characters live in proximity, making it easier for secrets to surface. The confined space of the third-floor flat intensifies tension, as Poirot can interact with suspects easily, keeping the investigation immediate and contained.
Told from Poirot's point of view, the story lets viewers follow his precise thought process. This perspective draws the audience into the mystery as Poirot uncovers clues gradually, building suspense and showcasing his cleverness. The focused POV makes the final reveal satisfying, as each detail falls into place through Poirot’s deductions.