The story begins with Anthony Bridgerton making the decision to marry. He suffers from a fear of falling in love as he believes he will die young like his father, and cannot bear to lose a loving wife. His desire to marry only stems from a need to produce and heir.
Anthony has his eyes set on Edwina Sheffield, the diamond of the season. However, his plans to marry her are thwarted by her sister, Katharine “Kate” Sheffield, who does not think him good enough for her sister. Though they despise each other, the two are often in situations alone with each other, which leads to a friendship of sorts forming.
Eventually, Kate falls in love with Anthony but realizes that she cannot have him. Instead she gives him permission to marry her sister. However, the two are caught in a compromising position by the public, forcing them to get married. Despite his feelings for her, Anthony tells Kate they can only be friends who are married, and he cannot ever love her.
But this all changes when Kate is in a carriage accident. Believing she is dying, Anthony confesses his love for her and tells her he only pushed her away out of fear of losing her by dying early like his father. It turns out Kate only has a broken leg and she and Anthony live happily ever after.
