After killing a traitorous MI6 section chief—who has been selling classified information—and the chief's contact, James Bond receives his double-0 status and is designated 007. He then travels to Madagascar in pursuit of Mollaka, a globe-trotting bombmaker-for-hire. After a parkour chase to an embassy, Bond kills Mollaka and escapes by setting off an explosion. Searching through Mollaka's mobile phone, Bond discovers a text message, which he traces to Alex Dimitrios, an associate of the banker and terrorist financier Le Chiffre. Le Chiffre's investments involve short-selling stock in successful companies using his clients' money, and then engineering terrorist attacks to sink their share prices, creating huge profits for himself.
Bond travels to the Bahamas—where Dimitrios has a home—and seduces his wife, Solange Dimitrios. After answering a phone call, Solange reveals that her husband is flying to Miami, so Bond leaves to pursue him. In Miami, 007 kills Dimitrios and follows Le Chiffre's henchman, Carlos, to Miami International Airport. There, Bond foils Le Chiffre's plan to destroy the prototype Skyfleet airliner by stopping the fuel truck Carlos was planning to crash into the aeroplane and then killing Carlos.
Left with a huge loss and under pressure to recoup his terrorist clients' money, Le Chiffre sets up a high-stakes Texas hold 'em tournament at the Casino Royale in Montenegro. Hoping that a defeat would force Le Chiffre to aid the British government in exchange for protection from his creditors, MI6 enters Bond into the tournament. On the train to Montenegro, Bond meets Vesper Lynd, a British Treasury agent whose role is to protect the government's interests, specifically the $10 million buy-in. In Montenegro, Bond meets a local MI6 contact, René Mathis, who manages to have both the Chief of Police and Le Chiffre's lieutenant arrested, placing more pressure on Le Chiffre. In the tournament, Bond loses his initial stake on a misplayed hand, and Vesper refuses to give him $5 million to continue playing. Frustrated by his failure, Bond resolves to assassinate Le Chiffre. Before he can, a fellow player, Felix Leiter, reveals himself as a CIA agent. Leiter offers to stake Bond in exchange for custody of Le Chiffre. Back in the game, Bond rapidly re-establishes his pot. Le Chiffre attempts to have Bond killed by having his girlfriend Valenka poison Bond's drink, but he survives with the help of Vesper. Bond wins the tournament, and the winnings are deposited into a Swiss bank account. Soon afterward, Le Chiffre's henchmen abduct Vesper and use her as bait to capture Bond.
Le Chiffre tortures Bond for the bank account's password, but he is interrupted by Mr. White, who kills Le Chiffre for being untrustworthy. Bond awakens in a hospital on Lake Como and has Mathis, whom Le Chiffre falsely identified as a double agent, arrested. Bond admits to Vesper that he is in love with her, and posts his resignation to M. The couple travel to Venice, where Bond learns that his winnings were never deposited in the Treasury's account. Realising that Vesper had stolen the winnings, he pursues her and the men to whom she gives the money into a building under renovation. In the ensuing firefight, the inflatable supports holding the building above water are punctured. Bond kills the men and tries to rescue Vesper, but she locks herself in an iron-frame lift and allows herself to drown as the building sinks. Mr. White, watching from a nearby balcony, walks away with the money.
Bond rejoins MI6 and learns that Vesper had a French-Algerian boyfriend who was kidnapped by the organisation behind Le Chiffre and Mr. White to blackmail her into co-operation. Bond is also informed that Vesper agreed to deliver the winnings in exchange for Bond's life. Bond then discovers a text from Vesper with White's name and mobile phone number, which he uses to find White. After wounding and capturing White, he introduces himself: "The name's Bond—James Bond."