Playboy Anthony Richmond, portrayed by Sean Connery, concocts a cunning plan to seize his uncle Charles Richmond's vast fortune of £50 million. Charles, a domineering and arrogant tycoon confined to a wheelchair, becomes the unsuspecting target of Anthony's devious scheme. To carry out his plot, Anthony hires the naive yet sincere Maria Marcello, played by Gina Lollobrigida, convincing her to marry the old man in exchange for an enticing sum of one million pounds.
As the story unfolds, the audience witnesses Maria bravely endure the relentless emotional and verbal abuse inflicted by Charles, both at his lavish estate and during a turbulent yacht trip in the picturesque backdrop of Mallorca, Spain. It is during this trip that they tie the knot, and in a unexpected turn of events, a humbled Charles alters his will, leaving his entire fortune to Maria, while his greedy nephew, Anthony, is only granted a measly £40,000.
However, tragedy strikes when Charles passes away on the yacht under mysterious circumstances. In an audacious twist, both Anthony and Maria devise a plan to maintain the illusion that Charles is still alive as they return to the estate. As tensions rise, Maria finds herself under suspicion for murder after she confesses their elaborate ruse to the detectives. It is then she learns about Anthony's dark reality: he had poisoned his own uncle with barbiturate poison and cunningly deceived Maria about Charles's last will, intending to frame her for the crime and secure the fortune for himself once she is convicted.
The plot thickens as detectives Lomer and the loyal servant Thomas, played by the enigmatic Johnny Sekka, uncover a shocking tape recording left by Charles on his deathbed. This recording unveils Anthony's treachery and his role in the murder. In a frantic attempt to escape his impending fate, Anthony finds himself face-to-face with consequence. As the wheelchair containing Charles is pushed towards him, he meets his demise by tumbling down the grand staircase, all while a ghostly apparition of Charles looms ominously above.
In the conclusion of this thrilling tale, justice prevails as Maria proves her innocence in court, emerging victorious and inheriting Charles's estate and fortune. The film closes on a triumphant note, with Maria finally free from the shackles of Anthony’s treachery. This captivating story ultimately reflects the duality of trust and betrayal, showcasing how the unsuspecting can navigate the treacherous waters of deception, leading to a satisfying yet somber resolution.
