While visiting the grave of his deceased wife, Tracy, James Bond is called back to MI6 headquarters. A helicopter arrives to transport him. During the flight the pilot is killed by electricity that surges through his headset and a familiar voice begins to taunt Bond over the chopper's loudspeaker; it is that of Blofeld, Bond's deadliest villain. As Bond struggles to gain control of the chopper, he notices a man in a motorized wheelchair nearby. Bond manages to reach the pilot's seat but cannot operate the 'copter. Blofeld, controlling the 'copter with a small console, flies the chopper into a giant foundry building, with the intention of letting it crash. Bond realizes that a set of cables have been wired to the chopper and he rips them out, regaining control of it. He flies after Blofeld and hooks his wheelchair on the end of the chopper's landing skid. Though Blofeld pleads for his life, Bond vengefully drops him down a nearby smokestack.

In the Adriatic Sea, a fishing ship, the St. Georges, trawls off the coast of Albania. Inside is a hidden control room for British defense. The spy ship is equipped with ATAC (Automatic Targeting and Attack Communicator), a valuable defensive and offensive device that the Soviet Union would like to obtain. When the ship's decoy fishing crew hauls in a net, it brings with it an old anti-warship mine which explodes, sinking the St. Georges. At MI6, M's temporary replacement, Tanner, is informed of the incident. When he asks how deep the water is off the coast of Albania, he is told it isn't "deep enough." Hoping to find the St. Georges and the ATAC discreetly, Tanner orders a British underwater archeologist, Havelock, to find the St. Georges.

Havelock's daughter, Melina, arrives by plane at her father's yacht near the site of the St. Georges' sinking. While she reunites with her parents the plane she was brought in suddenly strafes the yacht with a burst of machine-gun fire. Both Havelock and his wife are killed, however Melina is unharmed.

James Bond is called into M's office to meet with Tanner and Minister of Defense Gray. He is ordered to find the ATAC, his first lead being the man, Hector Gonzales, who killed the Havelocks. Tanner orders Bond to find Gonzales near Madrid and interrogate him for information. Bond goes to Gonzales' home where he's throwing a party. Bond observes that Gonzales is meeting with a mysterious man who is paying him, most likely for the assassination he performed. Bond is captured by security and brought to Gonzales who identifies him immediately as British Secret Service & orders him taken away. As he dives into his pool, Gonzales is struck by a crossbow bolt. The distraction allows Bond to escape; as he does, a would-be killer is killed, also by a crossbow bolt. The shooter is Melina Havelock, who has been seeking revenge for the deaths of her parents. Before they can escape in Bond's Lotus Esprit, it explodes when a guard tries to break one of it's windows. Bond and Melina use her car in a furious chase where they evade Gonzales' men.

Bond reports back to MI6, where Tanner reprimands him for failing to obtain any information from Gonzales. However, Bond, with Q's assistance, uses a highly sophisticated database called an Identigraph, to identify and locate the man who was paying Gonzalez. The man is Emile Leopold Locque, a Belgian assassin and crime lord, who may be in Cortina d'Ampezzo in northern Italy.

Bond reports to Cortina and meets his contact, Ferrara, who tells him that Locque may be associated with an organization called the White Dove (indicated by the pin Locque & it's members wear). Bond meets socially with a former Greek gangster named Aris Cristatos, who tells him that Locque's employer is Milos Columbo, Cristatos' former organized crime partner. Cristatos asks Bond to be an escort for his young skating protege while she watches the biathlon, Bibi Dahl. Bibi tries to seduce Bond in his hotel room but Bond refuses. At the biathlon, Bibi points out a friend of hers, Eric Kriegler, a competitor in the event. Bond bids Bibi farewell and leaves the event; as he skis away, he is attacked by a small group of thugs on winterized motorcycles. One of them is Kriegler himself, who tries to kill Bond with his sniper's rifle, another is Locque. Bond is able to escape his attackers, killing several of them in the process.

Bond meets Bibi later at the Olympic skating rink where Bibi is practicing. He asks her about Eric & finds out that he is an East German defector. After Bibi leaves, he is again attacked, this time by three hulking hockey players. Bond beats them all and returns to his car. There he finds that Ferrara has been killed. In Ferrara's dead hand is a White Dove pin. Bond goes to the business section of Cortina the next day and spots Melina buying a crossbow. As he approaches her, they are both attacked by men on motorcycles, much like Bond the previous day. Bond kills both attackers and orders Melina to leave Cortina. He also tells her that her need for revenge may get her killed too. She agrees to return to her father's yacht and wait for word from Bond.

Bond reports to Greece to continue his investigation of Columbo. At a nightclub, he meets with Cristatos again and asks how to meet Columbo. Columbo is at the same club and is sitting with a woman, Lisle von Schlaf, a countess. She becomes openly insulted by one of Columbo's comments and goes back to her hotel with Bond. The two spend the night together, Bond hoping to discover more information about Columbo. In the morning, the two walk on the beach and are attacked by two White Dove members, one of whom is Locque. Locque kills Lisle by running her down in his dune buggy and he and his accomplice capture Bond. Locque's man is suddenly shot by a harpoon and several men wearing the White Dove emblem appear out of the surf and capture Bond. Bond is taken to Columbo himself, who tries to convince the spy that Cristatos is actually behind the search for the ATAC. Bond accompanies Columbo and his crew on a raid at one of Cristatos' smuggling ports where Bond finds Locque at work. He chases Locque through the fortress that serves as Cristatos' base and corners the assassin on a cliff. He shows him the dove pin he'd gotten from Ferrara, throws it to Locque and the tiny shift in weight causes the car to slide off the cliff; Bond gives the car a hard kick & it plummets, killing Locque.

Bond travels to the Havelock's yacht and finds Melina. Bond asks Melina if her father possibly left behind any information about his work for the British government. Melina shows Bond her father's journal and they discover that her father had been diving in an unusual underwater location. The two go there in her father's mini-submarine and find the St. Georges. The enter the wreck and find the ATAC attached to an explosive charge which had failed to be activated. Bond disarms the bomb and takes the ATAC when the two are attacked by a diver in a JIM suit. Bond manages to escape the killer and attaches the ATAC bomb to the JIM suit, destroying it. Nearly out of breathable air, he and Melina return to the mini-sub but are again attacked by another mini-sub. They are able to escape this man as well. They return to the surface to find that Cristatos has seized the Havelock yacht and killed the crew. Cristatos takes the ATAC with the intention of selling it to the Soviet government. Using Melina and Bond as "bait" they tow them behind Cristatos' yacht hoping that sharks will eat them. Bond is able to snap the line binding them and they retreat to a SCUBA tank Melina left on the ocean floor. Cristatos, assuming Bond and Melina are both dead, leaves. The two make it back to their yacht and hear her father's parrot reveal the destination of the ATAC, a location only called St. Cyril's. Q informs Bond that there are over 300 locations with the same name in all of Greece, however, Bond knows that Columbo will know where Cristatos has retreated to.

The St. Cyril's that Columbo knows of is a monastery in the northern mountains of Greece and sits atop a series of sheer cliffs. It is only accessible on the ground by a cabled basket; Bond must scale the cliff to reach the machinery controlling the basket. As he climbs, he is found by one of Cristatos' men, who tries to loosen the spikes and climbing rope Bond is using as a safety line. Bond is able to make it up the cliff far enough to throw a spike at the man and send him off the cliff. He makes it the basket house and lowers it for the rest of the crew to come up.

Bond quickly finds himself in a combat struggle with Eric Kriegler, who is Cristatos' KGB contact. General Gogol is on his way to the monastery to collect the ATAC. While the rest of their party and Columbo take out Cristatos' men, Bond takes out Kriegler. Columbo, though injured in the fight, is able to kill Cristatos. Gogol arrives and genially asks for the ATAC; Bond suddenly throws it over the side of the mountain where it shatters hundreds of feet below. Gogol is visibly shocked at first but Bond replies "Detente, Comrade! You don't have it, I don't have it." Gogol suddenly smiles and leaves, obviously humored.

Melina and Bond share a romantic evening on board the Havelock yacht when a call arrives from MI6 on Bond's wristwatch. The British Prime Minister, Margaret Thatcher wishes to speak to Bond personally. Bond gives the watch to Melina's parrot and the PM is tricked into thinking she's still speaking to Bond, who has joined Melina for a nude moonlight swim.