Arthur Jones occupies the position of the third child among five siblings in the affluent Jones family. A boarding student and prefect at Eton College, he sets his sights on further study at Oxford University. He presents with blond hair, blue eyes, and average height, typically attired in a grey suit and blue tie – a contrast to his older brother William's frequent top hat.

His personality is marked by practicality, a stern disposition, and a grumpy demeanor. Arthur often displays emotional reserve, appearing cold or arrogant. This extends to family interactions, where he exhibits social awkwardness, such as abruptly walking away from conversations he finds challenging, like one with Emma during her visit. He maintains a distant relationship with most siblings, frequently arguing with his younger sister Vivian due to his bluntness, though he shares a slightly closer rapport with his younger brother Colin, once grouping them together as "men".

A significant element of his role is his pragmatic disapproval of William's romantic involvement with Emma, a maid. Arthur deems it illogical for gentry to marry outside their social class and warns William of the societal repercussions. This stance stems partly from his belief that William, as the heir, is too lenient and ill-suited for the responsibility, coupled with Arthur's quiet envy of William's position. Arthur believes his own disciplined nature makes him better qualified to inherit and manage the family business.

His relationship with his father, Richard Jones, is characterized by compliance; Arthur acquiesces to Richard's decisions concerning the family business succession. His past and childhood remain largely unexplored in the documented narrative, and his character does not undergo significant development or resolution within the main storyline, serving instead to emphasize the family's internal conflicts surrounding class and duty.