Third Girl

Hercule Poirot is drawn into a complex and troubling case when a young woman, Norma Restarick, bursts into his flat, declaring she may have committed murder, only to flee in distress. Bewildered, Poirot enlists the aid of his old friend, crime novelist Ariadne Oliver, who had briefly encountered Norma and recognized her disturbed state. Together, they embark on a quest to understand Norma's cryptic confession and unravel the truth behind her anxieties. Their investigation leads them into a tangled web involving Norma's estranged father, a controlling stepmother, a missing flatmate, and a past tragedy. As Poirot and Oliver delve deeper, they uncover secrets, deceptions, and hidden motives within London's bohemian art scene and affluent circles, realizing that Norma might be a pawn in a larger, more sinister game. The 'third girl' of the title eventually becomes a crucial piece of the puzzle, forcing Poirot to use all his psychological acumen to expose a ruthless killer before Norma becomes the next victim or is wrongly accused.