
15 plot points

Manhattan. Roger Thornhill, advertising executive, smooth-talking, superficial, divorced twice. Dictating messages to secretary. Comfortable in his privilege. Mistaken identity about to destroy carefully managed life.
Mother to Roger: "You always were a little bit too clever for your own good." Theme of false identity vs. true self, and becoming the hero you pretend to be.
Roger at Plaza Hotel. Raises hand at wrong moment, mistaken for George Kaplan, government agent who does not exist. Kidnapped by thugs. Taken to mansion, interrogated by Vandamm. Thinks it is mistake. About to get worse.
Vandamm tries to kill Roger, forcing him to drink bourbon and drive drunk off cliff. Roger escapes, arrested for DUI. No one believes his story. Police find nothing at mansion. Framed for drunk driving. Old life credibility crumbling.
Should Roger go to police or investigate himself? Searches for real George Kaplan at hotel. Empty room, clothes his size. Set up perfectly. Kaplan does not exist. Conspiracy deeper than expected. Must clear name.
Roger goes to UN to meet Vandamm. Lester Townsend, real diplomat, murdered. Roger photographed with knife. Framed for murder. Must run. Enters world of fugitive. No longer advertising man, now hunted.
Roger meets Eve Kendall on train to Chicago. Beautiful, mysterious, helps hide him. Romance blooms. Sleeps together. She arranges meeting with Kaplan. But she is Vandamm lover, setting Roger up. Love and betrayal.
Crop duster scene. Roger sent to remote field. Plane attacks. No place to hide. Survives. Confronts Eve at auction. Vandamm there. Roger causes scene to get arrested for safety. Promise: elaborate set pieces and narrow escapes.
Professor reveals truth: Kaplan does not exist, invented to distract from real agent Eve. She is undercover. Shooting Roger was fake. False victory: understands conspiracy now. But Eve in danger. Must save her. Stakes raised.
Roger poses as Kaplan to help Eve. Vandamm suspicious of Eve. Plans to kill her on plane after leaving country. Roger must convince Eve to escape without blowing cover. Layers of deception. Time running out.
Eve refuses to escape, loyal to mission. Roger desperate. Vandamm discovers Eve is agent. Will kill her. Roger helpless. Professor will not risk operation to save her. Woman he loves about to die.
Roger at Mount Rushmore. Eve being taken to plane. He has no plan, no help, no weapons. Must improvise. Advertising man must become actual hero. No more pretending. Real courage required.
Roger infiltrates Vandamm house. Fights henchman. Rescues Eve. Synthesis: the fake identity of hero became real through action. He actually is the spy he was mistaken for. Became role through necessity.
Chase across Mount Rushmore faces. Hanging from Lincoln nose. Eve slipping. Roger pulls her up. Vandamm defeated. Government saves them. Superficial ad man became genuine hero through ordeal. Transformed.
Train compartment. Roger and Eve married. "Come along, Mrs. Thornhill." Train enters tunnel. Perfect Hitchcock ending. Wrong man became right man. Marriage number three might actually work. Adventure complete.