|“||By the time this journey is over, your life will have changed completely.||”|
James comes from a distinguish family where his father's from a line of prestigious lawyers and his mother's from nobility. His parents were often away from home and very strict with him, so he considered his nanny and butler to be his real parents for they raised him like their child. He grew up in a idyllic childhood where he had everything a child could want, but lacked freedom.
However, his nanny had kidnapped him in order to extort money and it was the first time he witnessed "evil". It was there he met Sebastian Moran, a street urchin, and helped him escape. He would later go to the best schools in England and became a mathematics professor. He also created the criminal organization called "M", as well as the leader "M", where he used his intelligence and wealth to committed numerous crimes. His crimes earned him the title "The Napoleon of Crime".
Two years before the prologue, he was already a fan of Jane Marple when she played Irene Adler in the Mid-Fall Murders and had met Sherlock and John while an episode of the series was being filmed.
James has distinguishing silver hair and amber eyes and often wears expensive suits with a blue rose lapel pin. His looks, charisma, and wealth attract many people, which easily makes him able to manipulate the feelings of others for his own gain.
Because he was born with immense wealth, he's willing to spend a significant amount of money without batting a eyelash; for him, there's no such thing as too much. He often uses money to obtain what he wants, but if it can't be bought then he'll use any criminal means. Although not a murderer, it's revealed that he organized the deaths of certain members of his organization because they betrayed them or they were a threat of the organization being exposed, and nearly killed Sherlock during their battle on the Reichenbach Express.
He's completely enamored with Jane and attracted to her intelligence, charm, and beauty. He often tries to win her over by giving outlandishly lavish gifts such as a wardrobe full of dresses everyday, which she often declines to accept; however, this only attracts him more because of her modesty. Despite Jane in love with another guy in other routes, he's determined to win her heart and believes that he's the love of her life.
- James' main story, "Robbery on the Reichenbach Express" is loosely based on Sir Arthur Conan Doyle's short story "The Final Problem"