Hosts a lavish party and uses a blackmail note to betroth his daughter Madge to Oliver Whyte. Later breaks the engagement with Duncan Calton's advice. Secretly had an affair with Rosanna Moore, resulting in a daughter, Sarah (Sal). Suffers a fatal heart attack upon discovering Sal's true identity and his dropped marriage certificate. Leaves a substantial estate to Sal.
Frettlby is Madge's biological father, though their relationship is complicated by his hidden past and illegitimate lineage.
Frettlby and Rosanna were once married in a youthful passion, a secret that resurfaces to drive the plot.
Sal is Frettlby's illegitimate daughter, a fact concealed for decades until the investigation uncovers it.
Fitzgerald and Frettlby are rivals over Madge's affection, with Fitzgerald actively opposing Frettlby's matchmaking.
Calton serves as Frettlby's closest confidant and legal advisor, guiding him through personal and criminal crises.
Explore the full interactive character relationship map of The Mystery of a Hansom Cab