With the exception of Grant, the American agents have low regard for Bergman's character and an indifference to her fate.

Bergman and Grant have a Rio romance. Bergman says her character is reformed, Grant is skeptical. The unknown assignment turns out to be Bergman winning and spying on a former rejected paramour, Claude Rains. Bergman takes the assignment, although it means a break-up with Grant, sharing company and bed with creepy Rains, and putting her life at risk. Rains pounces on the bait (Bergman is very lovely) and they soon are engaged and married.

The German agents are ruthless and murder an associate who is prone to mistakes. There is something secretive about their champagne bottles, and Bergman cannot get access to the wine cellar. Grant suggests Bergman throw a big party, so Grant can check out the cellar. Common sense would have Bergman draw up a floor plan for Grant prior to the party, and Grant would bring a date to watch the cellar door while Grant checks it out. But for dramatic purposes, Bergman must lead Grant to the cellar and guard it. Grant accidentally busts a bottle. It is filled with "vintage sand" that is later found to be uranium ore. Grant hastily cleans up his mess, but unluckily Rains shows up. Grant kisses Bergman to make it look like a romantic encounter rather than espionage.

But Rains is no dummy, and he later investigates the cellar. Hitchcock deserves his "master of suspense" title, as he prolongs the tension in these scenes. We learn why Rains still lives his with domineering mother: he needs her advice. He knows his now hated wife is a spy, but his life is in jeopardy from his compatriots if she is discovered. Sinister mother comes up with a plan to slowly poison Bergman, first to sicken her, later to kill her.

Bergman is sick and looks it on a rendezvous with Grant. He is suspicious, but buys her story of a drunken binge. Bergman eventually realizes her fate (in another well-directed sequence involving her coffee) but is too late. She is bedridden and isolated. Lucky for her, Grant comes to the house to investigate, and carries her downstairs. Of course he soon meets Rains and his mother, with a group of German compatriots suspiciously viewing the scene. Rains cannot stop Grant without causing a disturbance that could lead to his death.

Grant flees with Bergman to the hospital, refusing to take Rains along, who is begging for a ride. Now Rains must face the German agents, who have many questions to ask of him.

Notorious has an excellent script and cast, and many extremely well-directed scenes.