Every end has a beginning and Colleen Hoover's fans have been awaiting the start of this story for ages.

Seven years after It Ends With Us became a New York Times bestseller, the author's beloved novel is finally getting the film treatment. Colleen caused a #BookTok shock when she took to Instagram on Jan. 26 to announce that Gossip Girl's Blake Lively and Jane the Virgin alum Justin Baldoni were set to star in the big screen adaptation of It Ends With Us. 

Since then, more information has slowly trickled out about the highly anticipated project, including additional cast members and an open casting call to find an actor to portray a younger version of Blake. And on May 16, the first photos from the New York City set were released, which revealed Blake's bold new hair color.

And while some fans seemed to take offense to how Blake's Lily has been dressed for the film—she's been seen in oversized jackets and billowing skirts—Colleen has no qualms about it.

"I don't remember describing outfits at all," the author said on TODAY June 23. "I don't care what they have on. In my head, it's about the conversation they're having and the story. It's the same way in the movie."

"You've seen a couple of outfits that are completely out of context," she continued. "I'm not worried about it."

And Blake is not the only star to undergo a dramatic transformation for their character. So, what can you expect from the It Ends With Us movie? Let's start at the beginning...

Gird your loins as pop culture's next great love triangle is about to begin. Based on Colleen Hoover's bestselling 2016 novel of the same name, which dominated TikTok in 2022, It Ends With Us is bringing to life the romance drama centering on a beautiful florist. 

"Though coming from a complicated past, Lily Bloom has always known the life she wants," the film's synopsis read. "While living in Boston, she meets neurosurgeon Ryle Kincaid and believes she may very well have found her soul mate. Soon, however, questions arise about their relationship, and to complicate matters her high school love interest, Atlas Corrigan, comes back into the picture, putting her relationship with Ryle in jeopardy."

So, which actors are portraying Lily, Ryle and Atlas? 

"A flower that's still blooming." 

That is how the film's official Instagram account described the Gossip Girl alum's character, who is the florist at the center of a love triangle. To portray the beloved character, Blake dyed her signature blonde tresses red. Fans got their first look at Blake's fiery new hue when she was spotted on the New York City set on May 16.

Not only will Justin Baldoni portray Lily's complicated doctor love interest, but the Jane the Virgin star is also directing the movie. 

As for the rest of the behind-the-scenes team, both Justin and Blake as well as Colleen will have creative say as executive producers. Other producers include Alex Saks (The Florida Project) and Christy Hall (I Am Not Okay With This), who is writing the script, per a press release from Wayfarer Studios and Sony Pictures.

Blake isn't the only cast member changing up her hairstyle for her character as Justin chopped off his long hair prior to filming to achieve Ryle's clean-cut look. Justin documented his haircut in an April 15 Instagram video, revealing he was donating his strands to Locks of Love.

In addition to cutting his hair, Justin also revealed he was hitting the gym. "A lot of change in one week," Justin captioned an April 17 gym selfie. "Cut my hair. Started eating carbs. And now I'm seeking validation from strangers on the internet by posting thirst traps. Wait …is this a thirst trap? Just Googled it. Don't google thirst trap."

Brandon Sklenar—star of the Yellowstone spinoff 1923—is set to play Atlas, Lily's childhood friend and former flame who becomes a romantic rival for Ryle. 

Justin confirmed Brandon's casting on Twitter April 20, writing, "Ladies and gentleman… meet your #Atlas."

After the news was announced, Brandon took to Instagram to share a heartfelt message about joining the movie.

"When this project came along I wasn't aware of this book or the tremendous impact it has had on women all over the world in helping them to have the strength to change their lives," he wrote on April 21. "This is something very personal to me. The amount of women I've known who have been victims of abuse is staggering. It is our intention that this film continues to spread the vital message of this book; for women to feel empowered and men to be better. I'm honored to be a part of it."

It was announced May 1 that Jenny Slate had joined the film's roster as Allysa, Ryle's sister and Lily's best friend. "Pinch me," Justin wrote on Instagram of the Saturday Night Live alum's casting. "Hey sis!"

Describing Jenny as "one of the most talented humans," Colleen admitted on social media that she "can't even believe she'll be in this movie."

While the actress picked to portray a younger version of Blake has yet to be revealed publicly, Justin confirmed on April 19 that they have found their star following an extensive search that included an open casting call on social media.

"Thank you for being a part of the process, it was inspiring and all of the messages we received was just validation for why we're making this movie and why this movie is so important," he shared on Instagram. "We found our young Lily, we'll be announcing her soon."

It Ends With Us has yet to announce a release date.

This story was first published on Saturday, May 20, 2023 at 3 a.m. PT.