Meaning

Moriarty is speaking here with the cheerful self-awareness of someone who has fully embraced his own role in a larger story. Rather than denying or excusing his destructive nature, he frames it as a narrative necessity, something the story cannot do without. There is genuine wit in the observation, because it is true: heroes need opposition to matter, and a compelling villain gives the whole drama its stakes. What makes the line unsettling is how comfortable he is with the description, almost grateful for the part he gets to play.

Context

The line is delivered during a period of escalating confrontation between Moriarty and Holmes in the second series of BBC Sherlock. By A Scandal in Belgravia, Moriarty has already been established as Holmes's greatest enemy, and this remark belongs to a broader pattern of speeches in which he presents himself theatrically and with great relish. The writers gave Moriarty a quality of self-mythologizing that distinguishes him from most screen villains, making him feel like someone who has thought carefully about what he is and decided to enjoy it.

About the author

Jim Moriarty as depicted in BBC Sherlock is played by Andrew Scott and written as a gleefully theatrical criminal genius rather than the more shadowy figure of Doyle's original stories. The character originated in Arthur Conan Doyle's fiction as Holmes's ultimate nemesis, described as a criminal mastermind of extraordinary intelligence. Scott's performance in the BBC series attracted enormous praise for finding genuine menace within a flamboyant exterior. Moriarty has remained one of fiction's most enduring antagonists since Doyle introduced him in the late nineteenth century.