Sean Fleming (Michael Fassbender)

A newly operational MI6 field agent from Ireland who has a desire to become a 00 agent. His father Pierce was a member of the Irish Republican Army and ultimately died fighting the English when Sean was a toddler. He was one of the members that had participated in the kidnapping of the SAS lieutenant colonel Gareth Mallory early on his career. MI6 was the organization that put together an operation that led to his rescue, but killing most of the IRA soldiers in the process in a major firefight. (Something that the organization tries to keep secret from Sean) His mother Ann faced the pressure of living on her own and taking care of her son alone. She was already shattered by the death of her husband. She started to take on multiple jobs to try to support them, but she eventually gave in to the advances of one of her bosses, a wealthy and high ranking Englishman, who had promised to give her a raise if she submitted to him. It did not happen however, and when she tried to expose him she was condemned a liar and fired. That along with the deep sense of shame for what she had done and her perceived failure to her son led her to taking her own life.

Soon afterward MI6 brought him into their fold because of his status as an orphan and thus his lack of many strong personal ties. There he would met Alec Trevelyan, a fellow orphan and agent in training who attains 00 status a short while before Sean does. After becoming a field agent Sean strives to become a 00. During this time however Sean has actually started a relationship with a Londoner named Barbara Andres, one that he has hopes could escalate. He winds up teaming up with his idol James Bond, Agent 007, on a mission to take down the Quantum Organization. James becomes a mentor to him about how he should hold himself and treat others in the field. James asserts that in their line of work it would be dangerous for him to hold such a strong romantic tie. He cites his loss of Vesper Lynd as being one of the hardest parts of his life, and asserts that he hopes Sean never has to face anything like it.

During their time on the mission, Sean is put into positions where he finally has to kill. Eventually hitting the 00 pre-requisite of two and proving to be of great help to Bond throughout. Eventually however his identity and personal information is discovered which leads to Barbara being kidnapped. They confront him with her at gunpoint in order to force key information out of him. He struggles hard with the choice, though Barbara asserts that he should not tell them anything. An act that leads to her being knocked unconscious. Subsequently James manages to arrive, leading to Sean and he managing to take down the thugs. They subsequently take the battered Barbara to the hospital where Sean reminisces about what he wants in life. Happiness with Andres, or to be able to make a difference and help others as an agent.

They come to discover that a gang war has been brewing between Quantum and a once thought dead organization dated back to the Cold War known as Spectre that has its own part to play in all of this. In the end James gives his life in the line of duty, but in doing so succeeds in stopping Quantum's plans and killing their leader. Intelligence they manage to steal from their base subsequently leads to Quantum crumbling down once and for all. However agents of Spectre manage to get away with important materials that they plan to use for their own purposes. One of them being the one to kill Bond himself after he had Quantum's leader.

For his courage and skill displayed working on the mission, as well as attaining his first kills, Sean is promoted to 00 status and is awarded the designation 007. As his identity was compromised he also adopts the name James Bond as an alias to honor his friend and ally. Feeling the responsibility to carry on in James' place, swearing to take down the Spectre and their mysterious "Number One" he turns down his chance to return to a normal life to be with Barbara, and leaves her with a farewell. Apologizing for the danger he put her in, and says he hopes that she can find happiness with somebody else. She asserts that it will be hard, and that if he ever finds that he is finished with that businesses that maybe she could still be waiting for him.

=Trivia=
 * Sean Flemming's name is a homage to both the creator of the James Bond character (Ian Fleming) and the original actor to play Bond in the EON series of films (Sean Connery).