McClory was approached by Ian Fleming though their mutual friend
Ivar Bryce to produce the first Bond film. McClory argued that the novels as written were unsuitable for adaptation for the screen and that the character of Bond would have to be drastically rewritten. McClory began work on the new Bond with the help of Fleming and later with screenwriter Jack Whittingham. At the same time as he was rewriting the character, McClory began production on the first Bond film. Interest grew in what Fleming referred to as "Kevin's Bond" and major studios began to take notice of the project. Fleming had sold his interest in the film to McClory and Bryce's company Xanadu Productions for $50,000 and stood to gain little should the project be a hit. Fleming began writing the ninth James Bond novel, Thunderball, in January 1961 from his Jamaican home, Goldeneye Estate. His health was failing due to heart disease, and he was feeling burned out on Bond. He turned to a James Bond screenplay he had worked on in 1958, in collaboration with McClory, Jack Whittingham, and Ivar Bryce. When Thunderball was published in March 1961, Fleming failed to credit his collaborators for their part in the writing of the novel. McClory and Whittingham sued, in November 1963. The litigation lasted nine days (during which time Fleming suffered two heart attacks which significantly weakened his health), then McClory and Fleming settled the suit. Fleming admitted to the court that he had not credited his writing partners/co-authors. On December 3, 1963, the court ordered Fleming to assign and sell the film copyright of the novel and all copyrights in the screenplay to McClory, who was also awarded £35,000 plus court costs. Executives
Albert R. Broccoli and
Harry Saltzman, fearing a rival film, allowed McClory to receive sole producer credit on this film.
Richard Maibaum incorporated the newly-developed Bond character into
El satánico Dr. No (1962).
