'Bridgerton' season 3 ends on a happy note for Francesca Bridgerton and John Stirling. Here's what happens to them in the books.

• Francesca Bridgerton's love story begins in season three of "Bridgerton."
• However, it doesn't unfold until the sixth novel in Julia Quinn's "Bridgerton" book series.
• Here's what to know about her love interest John Stirling — and Francesca's eventual love story.

Warning: Major spoilers ahead for season three, part two of "Bridgerton," and "When He Was Wicked," the sixth Bridgerton book.

One romantic subplot in "Bridgerton" season three is almost as compelling as its main storyline.

While season leads Colin Bridgerton (Luke Newton) and Penelope Featherington (Nicola Coughlan) get their act together, another character also makes romantic inroads: Francesca (Hannah Dodd), the sixth Bridgerton sibling. After making her debut in society at the beginning of the season, she catches Queen Charlotte's eye and becomes a highly desired marriage prospect.

On the show, Francesca's approach to marriage is relatively utilitarian: While she hopes to find a compatible match, she doesn't want to put pressure on herself to find love, as her mother and siblings did. But it's not Lord Samadani, the Queen's pick for Francesca, who ultimately catches her eye. It's the Earl of Kilmartin, John Stirling (Victor Alli), a man whose reservedness matches Francesca's own.

They get married during a low-key ceremony at the Bridgerton house during the season three finale and prepare to move to John's primary estate in Scotland.

Here's what you need to know about Lord Kilmartin — and what to expect for Francesca's romantic future on Netflix's "Bridgerton."

Francesca and John marry in the 'Bridgerton' books too, but they're not married for long

In Julia Quinn's "Bridgerton" books, Francesca marries John. However, he suddenly dies two years into their marriage, when Francesca is 22 years old.

Though she's pregnant with John's child at the time of his death, she miscarries — meaning that John's cousin, Michael Stirling, becomes the new Earl of Kilmartin. After John's death, Francesca splits her time between London with her family and Scotland with John's family.

In the books, Michael actually falls in love with Francesca at first sight. Unfortunately for him, they meet just days before her wedding to John. After the marriage, they became close friends, but Michael becomes more reserved after John's death — and eventually, traveles to India.

Given that Michael doesn't marry after assuming his cousin's title, Francesca retains hers as the Countess of Kilmartin, managing the estate while Michael travels to India. But four years after John's death, Francesca wants to have a baby and seeks out another husband. Coincidentally, Michael has returned to London by then.

The tension simmers between the two, eventually tipping over into a proposal. Though reluctant, Francesca eventually agrees.

While the events of "When He Was Wicked" overlap somewhat with Colin and Penelope's story in "Romancing Mr. Bridgerton" in terms of in-universe chronology, the show has moved around some timelines from the books.

The 'Bridgerton' season three finale introduces John's cousin — with a major twist that will play out as the show continues

In the finale, Francesca is introduced to John's cousin Michaela (Masali Baduza), who will be traveling with them to Scotland. Immediately after meeting Michaela, Francesca becomes nervous and stutters while introducing herself. The scene, although brief, is a teaser for Francesca's next big romance with a gender-swapped version of John's cousin.

In finale interviews, showrunner Jess Brownell said that she had been pitching a queer storyline for Francesca since season one.

"I want to tell a story that accurately reflects a queer experience, and the first time I read Francesca's book, I really identified with it as a queer woman," Brownell told Teen Vogue. "Maybe not in the way Julia Quinn intended."

The show has yet to officially announce which Bridgerton's love story will be the focus of next season — though the finale heavily implies that it's Benedict — but Brownell told Decider that it was necessary to start planting the seeds for Francesca's trajectory during season three.

"Francesca's book, for those who are familiar, it takes place over a longer amount of years and it has more twists and turns," she said. "And so we felt like we wanted to start that story earlier so that we could play out more chapters of her book."

It's unclear when or how the TV show plans on handling John's death, but Brownell told The Hollywood Reporter that there will be a time jump at some point to give Francesca's relationships with John and Michaela adequate space.

"We're absolutely not denying the connection that Fran and John have, and when we tell the Francesca and Michaela story, we would definitely want there to be a time jump to give Francesca some time to earnestly mourn what she had with John," Brownell said.