Hyacinth Bridgerton is twenty-eight years old and happy with the idea of being a spinster who spends her days reading stories to the old Lady Danbury. However, her peace is disrupted one day by the return of Lady Danbury’s grandson, Gareth St. Clair. Gareth is in desperate need of money, having been cut off from his father years ago for refusing an arranged marriage.
Gareth requires Hyacinth’s help when he receives his grandmother’s diary and asks her to translate the Italian to English. He learns from the diary that there are family heirloom jewels worth a fortune hiding somewhere in his paternal family home. As such, Hyacinth and Gareth go on an adventure to locate these jewels. As they fail to locate the jewels time after time, they realize that they are both falling in love with the other.
Having fallen in love, Gareth proposes to Hyacinth, but this is ruined by his father who reveals the true nature of his birth through an affair his mother had with another man. Hyacinth believes he only proposed to spite his father, but eventually realizes that he truly loves her. The two marry and locate the missing jewels and live happily ever after.
