Catherine—called Little Bird or Birdy, daughter of Rollo and the lady Aislinn, sister to Edward and the abominable Robert, of the village of Stonebridge in the shire of Lincoln, in the country of England, in the hands of God—ranks right up there with heroines of pop culture known for their stubbornness and strength: Jo March (Little Women), Matilda (Matilda), and Hermione Granger (Harry Potter), to name a few. And now Catherine—like Jo, Matilda, and Hermione before her—has made the leap from the pages of a novel to the silver screen in Catherine, Called Birdy, an adaptation of the 1994 novel of the same name. Written and directed by Lena Dunham, the film is out Friday on Amazon Prime Video.

Dunham, perhaps best known for her dramedy TV series Girls, obtained the rights to Catherine, Called Birdy from the book’s author, Karen Cushman, almost a decade ago. In the spring of 2020, production was about to begin on the project when the pandemic hit. That extra time, though, gave Dunham the opportunity to sit with the script and revise it, leading to a softer, more complex relationship between the protagonist and her father (played by Fleabag’s Andrew Scott)—a sharp departure from the novel that becomes a defining characteristic of the film.

Why people love this book

News of the adaptation sparked some anxiety among the beloved book’s ardent fanbase. Catherine, Called Birdy has a dedicated following among members of a certain demographic (read: millennial women), whose childhoods were heavily shaped by the story.

“What I love is that the people who did read it, it was a cult book for them,” Dunham told the Hollywood Reporter. “It was one that they don’t forget. I am a huge YA fan, and what I loved about ’90s YA was how raw it was and how it didn’t question young people’s intelligence.”

The plot follows Catherine (or Birdy, or Little Bird) for a year through 13th century medieval England. Birdy has been gifted a journal by her older brother, Edward (a monk), and the lady Aislinn has agreed to free her daughter of her dreaded spinning chores in exchange for a documentation of Birdy’s days.

From there unfolds a regular, angsty, wide-eyed account of a 14-year-old girl’s daily life in 1290: embroidery, lady lessons, fleas, family tensions, and the looming threat of an arranged marriage. But the backbone of the book—visceral frustration with the unfairness of becoming a woman in society—rings clear and true through the centuries.

“For a particular age bracket of millennial women, this book was our first feminist guidebook,” writes Jeanna Kadlec for Nylon. “It taught us about consent, showed us that we alone owned our bodies and minds and futures.”

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What stayed the same in the adaptation

From the page to the screen, Birdy retains the timeless voice that made her an epitome of rebellion to fiercely independent teenage girls.

In a memorable moment from the book, a river in Stonebridge freezes over. Perkin (the goat boy) and Gerd (the miller’s son) polish bones from the kitchen and fasten them to their shoes to go ice skating, but Birdy isn’t allowed.

“I thought to make a list of all the things girls are not allowed to do,” she writes. “Go on crusades, be horse trainers, be monks, laugh very loud, wear breeches, drink in ale houses, cut their hair, piss in the fire to make it hiss, wear nothing, be alone, get sunburned, run, marry whom they will, glide on ice.”

In the movie, Birdy and Perkin (also her best friend) intercept the first of Birdy’s many suitors, a man from Kent (Russell Brand), and prank him, sending him away before he ever has a chance to reach the manor. When Birdy’s father finds out, he beats her on the hand with a rod.

“Things girls cannot do,” Birdy, played by Bella Ramsey, narrates. “Go on crusades, cut their hair, be horse trainers, laugh very loud, marry whom they will, be monks, drink in ale houses, go to hangings.”

Readers who fell for the young hero’s spunk in the face of the patriarchy will see it carefully preserved onscreen. But this is also a coming-of-age tale. In a bildungsroman, the main character grows—both morally and psychologically. In Catherine, Called Birdy, the main character learns that hope is a discipline.

“It occurred to me that what actually makes people married is not the church or the priest but their consent, their ‘I will,’” Birdy realizes in the book. “And I do not consent. Will never consent. ‘I will not.’ I cannot be wed without my consent, can I?”

A similar transformation appears in the film. “I feel something changed inside of me,” she says in the movie. “And just because I cannot be happy does not mean that I do not wish happiness for others. Joy is infectious, I am learning. I want to save Aelis. And I think I know a way—even if it means sacrifice.”

What changed

Fans of Fleabag will instantly recognize Andrew Scott in his role as Rollo, Birdy’s father, from his stint as “the hot priest” in the British dramedy. Fans of Catherine, Called Birdy will immediately realize that Scott plays Rollo with a softness and complexity that goes beyond the book.

“He really cracked the idea that this guy didn’t just have to be a brute,” Dunham told the Hollywood Reporter. “The same way that Birdy was stuck in her moment in history and she can’t bust out of it, he’s stuck in this thing that we’ve now coined ‘toxic masculinity,’ but let’s just say what he thinks is his duty. He’s a very flawed person, but there’s also a real gentleness to him.”

“He’s not the guy who can nail the sword fight, and he’s not the guy to drink you under the table,” she continued. “He doesn’t have whatever that traditional machismo of that moment is—he’s something different.”

The central conflict—whether or not Rollo can force an obstinate Birdy into marriage—defines the plot. In complicating his character, Scott adds humanity and empathy to a formerly two-dimensional man. That change, in turn, significantly alters the ending. In the film, Rollo eventually intervenes in the proposed marriage between his daughter and the vile Shaggy Beard (full name: Sir John Henry Murgaw), putting his own precious neck on the line.

“I thought what I’d love is for the ending to say, ‘She’s not free forever,’” Dunham told Vanity Fair. “She’s not going to be able to avoid marriage forever, but right now she has a chance to grow up a little more and she has a new perspective on her home and a new perspective on her father.’”