Millionaire Hugo Drax cheats at cards, the highest offense in polite English society. Special Agent James Bond is brought in to put Drax in his place, and Bond humiliates him in a tense game of bridge. After the game, Drax warns him that he had better spend his winnings quickly. Bond finds this comment suspicious but does not dwell on it at the time. Shortly after, Bond meets Drax again as he is assigned to work security at Drax's Moonraker facility where he is building a world class rocket that will be capable of carrying an atomic bomb to any city in Europe. Bond senses something suspicious but can find no evidence of contravention. The day before the launch of the Moonraker, Bond, with the assistance of police officer Gala Brand, discovers that Drax is actually a German agent working for the Soviets. He is planning on sending the Moonraker into the center of London and detonating an atomic bomb. Before they can warn anyone, Bond and Brand are captured and held captive. There are just hours to go before the plan is enacted, and Bond has to find someway to escape and stop the madman.

Sir Hugo Drax seems to be a shinning example of everything Britain can achieve. Following World War II, he is a soldier suffering from amnesia, with no idea who he is. The army doctors suspect he is an orphan named Hugo Drax, and he takes on this identity. Following the war, he makes millions in businesses abroad and then returns to England to spend his fortune. He donates to many worthy causes around the country and wins the love of the British public. During the cold war, he pledges to fund and create the Moonraker rocket, an enormous missile capable of delivering an atomic bomb to any city in Europe. Following a suspicious murder suicide at the Moonraker facility, Secret Agent James Bond is brought in to secretly observe the happenings the days before the first launch of the missile.

Bond is working with a police officer from Scotland Yard, the beautiful Gala Brand. Brand is also undercover as Drax's secretary at the Moonraker facility. Drax has brought in a team made up entirely of Germans to build the missile, all of whom Bond finds suspicious but cannot find anything solid to prove they are doing anything illegal. The day before the launch of the Moonraker, Bond and Brand are walking together on the beach when someone tries to kill them. They quickly realize it has to be someone working on the Moonraker but cannot tie it to Drax. As Brand is covertly spying on Drax, she discovers his true plans. He has secretly programmed the Moonraker to delived an atomic bomb into the center of London. Before she can warn anyone of her discovery, she is caught and held captive.

Bond is trying to rescue Brand but is subsequently captured himself. As Bond and Brand are tied up together, Drax tells them his story. He is not a Briton but a German. He took on the identity of Drax after the war and has been planning on extracting revenge on England for their part in humiliating German and himself during the war. He has been working with Russia to build the atomic bomb, and the German engineers are actually his former subordinates in the German army. They will all be escaping after the launch of the Moonraker. Drax leaves Bond and Brand alone, telling them they will be killed by the backfire of the rocket during the launching.

Before the launch, Bond and Brand manage to escape and hide in the Moonraker facility. With no time to spare before the destruction of London, Bond redirects the missile out to sea where it hits a Russian submarine carrying Drax and his team. Once London is saved, Bond is looking forward to starting a relationship with Brand. However, he is saddened when she rejects him due to her previous engagement to another man. Bond is faced with the success of the mission but the loss of the girl he has fallen for.