At the Day of the Dead parade in Mexico, Bond carries out an unauthorized mission to prevent a terrorist bombing on a stadium. After killing the men, Bond gives chase to the leader, Marco Sciarra. Bond hijacks Sciarra's helicopter, killing the pilot and Sciarra by causing them to fall to their deaths. In the process, he steals a ring from Sciarra, which features a stylised octopus as its logo. Sometime after the mission, M indefinitely suspends Bond from field duty. M himself is in the middle of a power struggle C, the leader of the Joint Intelligence Service, and is planning to form a global surveillance and intelligence program called "Nine Eyes". C also plans on closing down the 00 section since he believes it to be outdated.
Bond disobeys M's order and enters Rome to attend Sciarra's funeral. He then saves Sciarra's widow Lucia from several henchmen before seducing her, and she tells Bond about SPECTRE, a terrorist organization that her late husband had worked for. Using the ring he obtained from Sciarra, Bond enters a SPECTRE meeting under the guise of "Mickey Mouse", and identifies Franz Oberhauser as the leader. But Oberhauser manages to blow Bond's cover by calling out to Bond, and Bond flees, but he is soon chased by Mr. Hinx, an assassin for SPECTRE. Bond manages to escape from Hinx, and he is later told by Moneypenny that the information he gathered all lead to Mr. White, a member of Quantum which is revealed to be a division of SPECTRE, and that White has been targeted for assassination for abandoning the organization.
Bond finds White at his hideout in Austria, and notices White dying of thallium poisoning. He tells Bond that he had left Quantum and urges Bond to find and protect his daughter, Madeleine Swann, who will take him to a hotel called L'Americain, which will also lead him to SPECTRE's base of operations. Bond agrees, then White commits suicide. Bond later meets Swann and rescues her from Hinx, then meets up with Q. Q reveals through Sciarra's ring that Oberhauser was linked to Bond's previous missions, with Le Chiffre, Dominic Greene, and Raoul Silva being revealed to be SPECTRE agents. Swann also tells Bond that L'Americain is located in Tangier.
Bond and Swann arrive at the hotel and find that White had left whereabouts to Oberhauser's headquarters. They then travel by train and have dinner, but are soon attacked by Hinx. In the ensuing brawl, Bond manages to kill Hinx by hanging a chain around his neck and attaching it to a series of barrels and pushing them off the train, causing Hinx to fall. Bond and Swann then arrive at the SPECTRE headquarters, and once there, Oberhauser reveals that SPECTRE had been funding C and the Joint Intelligence Service while staging terrorist attacks around the world to create a need for Nine Eyes. This will allow SPECTRE to gain unlimited access to intelligence gathered by Nine Eyes. Oberhauser also reveals himself to be the mastermind behind all of Bond's troubles, mentioning Vesper Lynd and M's deaths. He plays a video of White committing suicide and Bond tries to turn off the broadcast, but a SPECTRE henchman subdues him. He convinces Swann to look at Bond and not at the video, and as soon as the video ends, Bond is knocked out by the henchman.
Bond awakens and finds himself strapped to a surgical chair, in which Oberhauser has several needles drilled into Bond's head. During the torture, Oberhauser reveals that at a young age, his father looked after Bond after Bond's parents died, and out of jealousy, he killed his father and faked his own death. Oberhauser then reveals that he no longer goes by the name Franz Oberhauser, he now goes by the name Ernst Stavro Blofeld. Before Blofeld can continue torturing Bond, Bond sets his explosive watch to one minute, and Swann throws the watch at Blofeld moments before it detonates, destroying the machine and knocking Blofeld unconscious. Bond and Swann then escape the base, destroying it in the process and leaving Blofeld for dead.
Bond and Swann return to London and meet with M, Q, Bill Tanner, and Moneypenny, and they plan to take down C at his headquarters. Swann decides to leave Bond, since she cannot afford to be included in the life Bond leads. However, on the way to the CNS building, the group is attacked and Bond is captured. The group proceeds with the plan without Bond. Bond's captors take him to the ruins of the Vauxhall Cross building and Bond kills his captors before entering the building. As Bond proceeds through the building, he comes across Blofeld hiding behind bulletproof glass, and finds that he is now blind in his right eye from the explosion at the SPECTRE base. Blofeld activates a time bomb, telling him that the building will be demolished in three minutes. He gives Bond a choice: Die trying to save Swann or save himself and live with the pain of not saving Swann for the rest of his life. Meanwhile, M and Q are in C's office and Q manages to disable the Nine Eyes program. M then fights C, in which M shoots the glass, causing C to fall to his death. Bond also manages to find Swann with 45 seconds to spare, then escapes on a speedboat into the Thames River. Bond spots Blofeld escaping on a helicopter and Bond chases after Blofeld, shooting down and destroying his helicopter in the process. The helicopter crashes onto Westminster Bridge. Blofeld is badly injured in the crash and crawls away from the wreckage, but Bond confronts him and Blofeld tells Bond to finish him off. Bond unloads the gun and states that he's out of bullets, then walks off with Swann and leaves Blofeld to be arrested by M.