In London, 1938, Ian Fleming is a dissolute playboy, eclipsed by his dead war hero father and successful brother. While propping up the bar at a jazz club, he meets Ann O'Neill, an alluring socialite. Unlike many of his conquests, Ann is more than a match for him. She already has a husband and a lover, Esmond Rothermere. Fleming finds solace in the arms of a beautiful dispatch rider named Muriel. Following a frosty morning-after encounter with Muriel, Fleming's domineering mother secures him a job assisting Naval Intelligence's Admiral John Godfrey. He quickly incurs Godfrey's wrath when he cooks up an unorthodox scheme to get information from two captured German submariners. However, Fleming's valuable findings make it apparent that an imaginative approach could be just what the war effort requires.

While training at a camp in Canada (Camp X), the Americans ask Fleming to use his talents to write a blueprint for a Central Intelligence Agency. On his return to London, Fleming persuades Godfrey to form the 30 Assault Unit - a group of the toughest soldiers prepared to play dirty, with Fleming serving as commanding officer. He believes the new unit of Intelligence Commandos is the key to beating the Nazis. Meanwhile, Fleming continues his relationship with Ann, but refuses to consider taking it to the next level, while Rothermere makes it clear he intends to win her over once and for all.

The war is nearly over, but Fleming is convinced the Nazis are hiding nuclear plans and that the British need to find them before the Russians. Finally, Fleming is granted permission to go to Germany to attempt to retrieve the plans. He succeeds in tracking down the documents, but comes face to face with The Werewolves (renegade German soldiers who will die before giving up the cause). Back in London, celebrations are underway, but the arrival of peace also means wartime relationships will have to be reassessed. Will Fleming and Ann finally find a way to be together? Moreover, with the war in its final throes, Fleming's days in Naval Intelligence are numbered - what other ways will he find to channel his ingenuity and imagination?