Sir James eventually learns that it is SMERSH who is behind the murders. Sir James politely declines, until a specific incident not only brings him out of retirement, but places him in the top job at MI6.
The womanizer who took over Sir James' name and number - who Sir James detests as sullying that good name and number by relying too much on gadgetry to get the work done - has moved onto other things, and Sir James' nebbish nephew Jimmy Bond has proved to be a disappointment as a spy and a man, and thus are not candidates for the job.
An unofficial and secret cooperative of the heads of British/French/American/Soviet intelligence try to persuade the original Sir James Bond 007 - known to be the greatest spy in history - to come out of retirement to work on a specific case: discover and stop the unknown forces that are murdering their collective agents.