Iris is an independent woman living in modern-day Edinburgh who becomes entangled in uncovering long-hidden truths about her family when she learns of a previously unknown relative.

Kitty is Esme’s older sister, favored by her family for her conventional behavior, whose life becomes intertwined with the broader patterns of family loyalty and personal ambition.

Alex is Iris’s former stepbrother, involved in a complicated relationship with her, as their past and present interactions are marked by social taboo and personal conflict.

Esme and Kitty’s parents are traditional, upper-class figures who rely on others to raise their children while primarily focusing on maintaining family reputation and arranging suitable marriages for their daughters.