Mr Bond, they have a saying in Chicago: "Once is happenstance. Twice is coincidence. The third time it's enemy action." Miami, Sandwich and now Geneva. I propose to wring the truth out of you.
Fleming structured the novel in three sections—"Happenstance", "Coincidence" and "Enemy action"—which was how Goldfinger described Bond's three seemingly coincidental meetings with him.
Whilst changing planes in Miami after closing down a Mexican heroin smuggling operation, British Secret Service operative James Bond is asked by Junius Du Pont, a rich American businessman (whom he briefly met and gambled with in Casino Royale ), to watch Auric Goldfinger, with whom Du Pont is playing Canasta in order to discover if he is cheating. Bond quickly realises that Goldfinger is indeed cheating with the aid of his female assistant, Jill Masterton, who is spying on DuPont's cards. Bond blackmails Goldfinger into admitting it and paying back DuPont's lost money; he also has a brief affair with Masterton. Back in London, Bond's superior, M, tasks him with determining how Goldfinger is smuggling gold out of the country: M also suspects Goldfinger of being connected to SMERSH and financing their western networks with his gold. Bond visits the Bank of England for a briefing with Colonel Smithers on the methods of gold smuggling.
Bond contrives to meet and have a round of golf with Goldfinger; Goldfinger attempts to win the golf match by cheating, but Bond turns the tables on him, beating him in the process. He is subsequently invited back to Goldfinger's mansion near Reculver where he narrowly escapes being caught on camera looking over the house. Goldfinger introduces Bond to his factotum, a Korean named Oddjob.
Issued by MI6 with an Aston Martin DB Mark III, Bond trails Goldfinger as he takes his vintage Rolls-Royce Silver Ghost (adapted with armour plating and armour-plated glass) via air ferry to Switzerland, driven by Oddjob. Bond manages to trace Goldfinger to a warehouse in Geneva where he finds that the armour of Goldfinger's car is actually white-gold, cast into panels at his Kent refinery. When the car reaches Goldfinger's factory in Switzerland (Enterprises Auric AG), he recasts the gold from the armour panels into aircraft seats and fits them to the Mecca Charter Airline, in which he holds a large stake. The gold is finally sold in India at a vast profit. Bond foils an assassination attempt on Goldfinger by Jill Masterton's sister, Tilly, to avenge Jill's death at Goldfinger's hands: he had painted her body with gold paint, which killed her. Bond and Tilly attempt to escape when the alarm is raised, but are captured.
Bond is tortured by Oddjob when he refuses to confess his role in trailing Goldfinger. In a desperate attempt to survive being cut in two by a circular saw, Bond offers to work for Goldfinger, a ruse that Goldfinger initially refuses, but then accepts. Bond and Tilly are subsequently taken to Goldfinger's operational headquarters in a warehouse in New York City. They are put to work as secretaries for a meeting between Goldfinger and several gangsters (including the Spangled Mob and the Mafia), who have been recruited to assist in "Operation Grand Slam"– the stealing of the United States gold reserves from Fort Knox. One of the gang leaders, Helmut Springer, refuses to join the operation and is killed by Oddjob. Learning that the operation includes the killing of the inhabitants of Fort Knox by introducing poison into the water supply, Bond manages to conceal a capsule containing a message into the toilet of Goldfinger's private plane, where he hopes it will be found and sent to Pinkertons, where his friend and ex-counterpart Felix Leiter now works.
Operation Grand Slam commences, and it turns out that Leiter has indeed found and acted on Bond's message. A battle commences, but Goldfinger escapes. Tilly, a lesbian, hopes that one of the gang leaders, Pussy Galore (leader of a gang of lesbian burglars), will protect her, but she is killed by Oddjob. Goldfinger, Oddjob and the mafia bosses all escape in the melee. Bond is drugged before his flight back to England and wakes to find he has been captured by Goldfinger, who has managed to hijack a BOAC jetliner. Bond manages to break a window, causing a depressurisation that blows Oddjob out of the plane; he then fights and strangles Goldfinger. At gunpoint, he forces the crew to ditch in the sea near the Canadian coast, where they are rescued by a nearby weathership.