The British information gathering vessel St Georges, which holds the Automatic Targeting Attack Communicator (ATAC), the system used by the Ministry of Defence to communicate with and co-ordinate the Royal Navy’s fleet of Polaris submarines, is sunk after accidentally trawling an old naval mine in the Ionian Sea. MI6 agent James Bond is ordered by the Minister of Defence, Sir Frederick Gray and MI6 Chief of Staff, Bill Tanner, to retrieve the ATAC before the Soviets, as the transmitter could order attacks by the submarines’ Polaris ballistic missiles.
The head of the KGB, General Gogol, has also learned of the fate of the St Georges and already notified his contact in Greece. A marine archaeologist, Sir Timothy Havelock, who had been asked by the British to secretly locate the St Georges, is murdered with his wife by a Cuban hitman, Hector Gonzales (played by Stefan Kalipha). Bond goes to Spain to find out who hired Gonzales.
While spying on Gonzales’ villa, Bond is captured by his men, but manages to escape as Gonzales is killed by a crossbow bolt. Outside, he finds the assassin was Melina Havelock, the daughter of Sir Timothy, and the two escape. With the help of Bond, Q uses computerised technology to identify the man Bond saw paying off Gonzales as Belgian underworld enforcer Emile Leopold Locque, and then goes to Locque’s possible base in Cortina, Italy. There Bond meets his contact, Luigi Ferrara, and a well-connected Greek businessman and intelligence informant, Aris Kristatos, who tells Bond that Locque is employed by Milos Columbo, known as “the Dove” in the Greek underworld, Kristatos’ former resistance partner during the Second World War. After Bond goes with Kristatos’ protégé, figure skater Bibi Dahl, to a biathlon course, a group of three men, which includes East German biathlete (and KGB agent) Eric Kriegler, chases Bond, trying to kill him. Bond escapes and then goes with Ferrara to bid Bibi farewell in an ice rink, where he fends off another attempt on his life by three men in ice hockey gear. Ferrara is killed in Bond’s car, with a dove pin in his hand. Bond then travels to Corfu in pursuit of Columbo.
There, at the casino, Bond meets Kristatos and asks how to meet Columbo, not knowing that Columbo’s men are secretly recording their conversation. After Columbo and his mistress, ‘Countess’ Lisl von Schlaf, argue, Bond offers to escort her home with Kristatos’ car and driver. The two then spend the night together. In the morning, Lisl and Bond are ambushed by Locque and his men, who run Lisl down, killing her. Bond is captured by Columbo’s men before Locque can kill him; Columbo then tells Bond that Locque was actually hired by Kristatos, who was a double agent during the resistance and is currently working for the KGB to retrieve the ATAC. To prove his accusation, Columbo and his crew take Bond on a raid on one of Kristatos’ opium-processing warehouses in Albania, where Bond encounters Locque and uncovers naval mines similar to the one that sank the St Georges, suggesting it was not an accident. After the warehouse is destroyed, Locque escapes; but Bond gives chase and kills him.
Bond then rendezvous with Melina on her yacht. Using her father’s daily log, they locate the St Georges and recover the ATAC from the wreckage. However, Kristatos is already waiting for them when they surface, and he takes the ATAC. After the two escape an assassination attempt through shark-infested waters, they discover Kristatos’ meeting point with the KGB with the help of Melina’s parrot, Max. With the help of Columbo and four of his men, Bond and Melina break into St Cyril’s, an abandoned mountaintop monastery. As Columbo confronts Kristatos, Bond kills Kriegler.
Bond retrieves the ATAC system and stops Melina from killing Kristatos after he surrenders. Kristatos tries to kill Bond with a hidden switchblade, but is killed by a knife thrown by Columbo; Gogol arrives by helicopter to collect the ATAC, but Bond throws it off the cliff, destroying it and declaring détente. Bond and Melina later spend a romantic evening aboard her yacht when he receives a call from the Prime Minister (in a cameo by Margaret Thatcher impersonator Janet Brown), leaving Max to flirt with the Prime Minister, much to the annoyance of Q, Grey, and Tanner.