This story contains spoilers from Bridgerton season three and the first four Bridgerton books.

Dear gentle reader, season three of Bridgerton is finally upon us. Well, the first half anyway.

The first four episodes of season three premiered on Netflix May 16 (part two drops June 13)—and after waiting over two years for an update on Lady Whistledown (voiced by Julie Andrews) and the rest of our favorite Regency era family, viewers finally get to see the love story between Colin Bridgerton (Luke Newton) and Penelope Featherington (Nicola Coughlan), affectionally known as Polin, blossom after years of friendship.

When we last left the Bridgertons in season two, eldest brother Anthony (Jonathan Bailey) had gotten himself into quite the love triangle, choosing between sisters Kate Sharma (Simone Ashley) and Edwina Sharma (Charithra Chandran). But as she did in the second Bridgerton book The Viscount Who Loved Me, Kate ultimately became as the queen bee and viewers were buzzing over Kanthony's happy ending. 

But season three is not based on book three An Offer From a Gentleman, but rather on author Julia Quinn's fourth Bridgerton book, Romancing Mister Bridgerton. And as with many book to screen adaptations, there are several key differences between the two mediums. Most crucially is the fact that the book takes place in 1824, 10 years after Anthony and Kate tied the knot, while the show is set only a few months after season two. Also at this point in the series, no one—not even the reader!—knows that Penelope is secretly Lady Whistledown, whereas Netflix viewers were let in on her identity in the first season.

Curious to find out how Bridgerton season three differs from the book? Keep reading to find out. 

In Netflix's version, Penelope Featherington (Nicola Coughlan) becomes our heroine, deciding that at only 19 years old it's time to give herself a full makeover in an effort to shed her wallflower ways and find a husband. To that end, she nixes the yellows and oranges she's worn for most of seasons one and two, instead opting for more flattering dresses and colors—oftentimes wearing the famed Bridgerton blue. Pen also gets help from Colin Bridgerton (Luke Newton), whom she has had a crush on for years, on how to improve her flirting techniques.

The circumstances are very different for book Penelope, who is already 28 years old in Romancing Mister Bridgerton, since the story is set in 1824, 10 years after Anthony Bridgerton (Jonathan Bailey) married Kate Sharma (Simone Ashley). Book Penelope is considered an old maid and her fashion transformation stems more from her mother finally leaving her alone after she doesn't get married. While book Pen is also stressed about being stuck with her mother for the rest of her life, it does not prompt her to find a husband.

Another major difference? No one—not even the reader!—knows that she's town gossip Lady Whistledown at the beginning of the book, a secret that only comes to light until about halfway through the fourth book; Netflix viewers, meanwhile, were treated to that bombshell in season one. 

Colin is our dashing young suitor in season three, and as has been the case for his character throughout the show, book Colin's trajectory is different from show Colin.

In the book, he is 33 years old and has been traveling extensively for years—as opposed to just a few months in the show—rarely leaving him at home. He also finds himself struggling to find his purpose, which he's slightly less concerned about on the show.

Much like on Netflix though, he finds his attraction to Penelope slowly growing throughout the book and spends much of his time marveling at just how kind, funny and stunning Pen is—all qualities he's shocked that he and the rest of the ton never noticed before.

In both the book and the show, emotions really come to a head for Colin and Penelope when she accidentally on purpose reads his travel diaries. Book Pen was visiting the Bridgertons because she's still best friends with Eloise Bridgerton (Claudia Jessie), while show Pen was at their house in episode two for private flirting lessons with Colin.

In both versions, Colin cuts his hand, although in the book it's on a letter opener and in the show it's because of a broken candle holder.

Regardless, it's as she is wrapping his hand that Colin really notices Penelope.

For Polin, in the book and show, their first kiss comes when Penelope directly asks him to lock lips, telling him she'll live her life having never been kissed if he doesn't do it.

On our TV screens, the moment occurs at the end of episode two, just after it's been revealed to all of the ton that Penelope asked for Colin's help in finding a suitor.

In the book, the kiss occurs in the Featherington drawing room when Colin visits Penelope to express his distress over the fact that he thinks his sister Eloise is Lady Whistledown (voiced by Julie Andrews).

Yes, in both the novels and the screen adaptation, Colin and Penelope's second kiss happens in a carriage just before he FINALLY proposes.

Netflix decided to make the kiss and proposal happen in the Featherington carriage at the end of episode four, just after Colin has ruined Penelope's chances with Lord Debling (Sam Phillips).

He doesn't yet know that she's Lady Whistledown, basically the Regency era DeuxMoi. In fact, episode one ends with Colin expressing his hatred for Lady Whistledown after she wrote some not-so-nice things about his "new" personality following his travels, telling sister Eloise that he will ruin whoever Whistledown really is.

In the book, Polin's carriage kiss and engagement occurs in Colin's coach after he's followed Penelope into town and learned her shocking secret: that she is, in fact, Lady Whistledown, meaning he goes into their marriage fully aware of her double life.

Francesca Bridgerton (Hannah Dodd) is unfortunately sometimes considered the forgotten Bridgerton child, not because her family doesn't love her, but because—as she does on the show—the sixth Bridgerton sibling prefers quiet and calm.

In the book series, it's casually mentioned that Francesca found her husband seven years before we pick up with Penelope and Colin. However, executive producer Shonda Rhimes and team have decided to combine some of the book plotlines with Francesca, Colin and Benedict Bridgerton (Luke Thompson) all searching for love in season three. That leads us to…

In the TV show, Francesca becomes Queen Charlotte's (Golda Rosheuvel) "diamond" of the season and finds herself being courted by the Queen's pick Lord Samadani (David Mumeni), as well as by her preferred suitor, John Stirling, Earl of Kilmartin (Victor Alli). (Sadly, Queen Charlotte is not a character in the books, meaning the monarch—and her truly fantastic headpieces—never anoints a "diamond" of any season.)

We'll avoid any more of the novel's spoilers about Francesca—as there's likely to be plenty of development on her in Bridgerton part two—but if you are interested in spoilers, her story is expanded upon in the sixth Bridgerton book, When He Was Wicked.

Those who have only watched the show might be surprised to learn that by the time Colin and Penelope get together in the books, Benedict has already been married for seven years and is quite a successful artist (book three, An Offer from a Gentleman—which Netflix skipped in favor of book four—tells his love story).

On the show, however, he is still trying to find his way in life as the second Bridgerton son, avoiding marriage and instead hooking up with a sassy widow, Lady Tilley Arnold (Hannah New). Viewers will have to see how his plotline unfolds in part two or a potential fourth season.

Eloise has a very different storyline on the show, namely that she is no longer friends with Penelope after she found out that Pen is Lady Whistledown. Eloise is instead BFFs with the ton's biggest bully Cressida Cowper (Jessica Madsen) after they bonded in the countryside.

Like book Penelope, book Eloise is also 28 years old—but unlike her double agent friend, Eloise has turned down six marriage proposals. Throughout Romancing Mister Bridgerton, there are also hints at Eloise's future, which gets its due in book five, To Sir Phillip, With Love.

As for her new best friend Cressida, while the show sees her still unmarried, in the book, she is already a widow and still a nuisance to Colin and Penelope.

The nature-obsessed Lord Debling is the ton's latest eligible bachelor this season—and the apple of Cressida Cowper's eye. Yet, he is a character purely created for the show and mainly acts as the catalyst to help Penelope come out of her shell, but, more importantly, to finally bring Colin and Penelope together.

Unfortunately, as much fun as it was to watch Colin save Penelope's life (with an assist from Lord Debling), the balloon event—and the very awkward conversation about birds—was purely made up for the show.

One of the biggest changes for the Featheringtons—in addition to how they got their fortune—is that the show has done away with Felicity, the fourth Featherington daughter, who is the sister Penelope is closest to, and also Hyacinth Bridgerton's (Florence Hunt) best friend.

In the books, Mrs. Featherington (Polly Walker) considers Felicity her last chance at a great match for one of her daughters, even suggesting that she should marry Colin.

As for sisters Prudence (Bessie Carter) and Phillippa (Harriet Cains), while on the show they are in a race to see who can have a baby boy first and continue the Featherington line, in the books they're less involved and are married to totally different characters.

Show Prudence is married to Harry Dankworth (James Phoon), while in the book she is married to a man named Robert Huxley. As for Phillippa, she is married to Albion Finch (Lorn Macdonald) in season three, whereas in the books she married Nigel Berbrooke (whom you might remember as one of Daphne's ill-mannered suitors in season one.)

In both the book and the show, Violet Bridgerton (Ruth Gemmell) is busy finding partners for her unmarried children. Book Violet has also long moved out of the Bridgerton house, and now lives at what the family loving calls Number Five (as they joke they couldn't come up with a better name). And while author Julia Quinn never gives a glimpse of Violet's life after all her children are married, the first half of season three hints at a possible romance for the Bridgerton matriarch with Lady Danbury's (Adjoa Andoh) brother Lord Marcus (Daniel Francis)—who does not exist in the books.

Another difference in the Bridgerton family? Youngest siblings Hyacinth and Gregory (Will Tilston) are much older in the fourth novel—with Hyacinth enjoying her first season and Gregory finishing his final term at Cambridge University—while the show finds them still in the background as their older siblings have the drama for the time being. However, we might be hearing more from them in future seasons, as Hyacinth's love story is told in book seven, It's in His Kiss, and Gregory's is book eight, On the Way to the Wedding.

The eldest Bridgerton sibling Anthony and his wife Kate had their love story told last season—based on the book The Viscount Who Loved Me—and the biggest changes for the new couple from book four to season three is that they're newly married and still living with Anthony's mother in Bridgerton house, unlike the books in which they've already been married for 10 years.

And the newlyweds are besotted with each other, which is luckily something found both on the show and in the book.

The second half of season three is set to debut on Netflix June 13, with four more episodes wrapping up Polin's love story. Check back then to find out what else they changed from book to screen.