After taking #BookTok by storm and reigning as the number one best-selling novel of 2022 and 2023—even outperforming the Bible—It Ends With Us has finally arrived on the big screen. Based on Colleen Hoover’s 2016 novel, the movie follows oh-so-conveniently-named flower shop owner Lily Blossom Bloom (played by Blake Lively) as she falls for charming but controlling neurosurgeon Ryle Kincaid (Justin Baldoni, who also directs)—just as her childhood love, Atlas Corrigan (Brandon Sklenar), reenters her life after years of estrangement.

Like Hoover’s book, the film version of It Ends With Us delves into how patterns of physical abuse from Lily’s childhood, when her father (Kevin McKidd) assaulted her mother (Amy Morton), get repeated in her own romantic relationships as an adult. Hoover previously told Today’s Jenna Bush Hager that she partly based her most popular book off the violence that her mother faced. “One of my earliest memories was him throwing a TV at her,” she said of her biological father. “There were no resources for women to leave situations like that.” Hoover said that her mother divorced her father when she was two. “She was able to get out of that relationship. And then from then on, I just remember growing up with a mother who was so strong and independent.”

Despite the embrace of It Ends With Us, the book has also drawn extensive backlash from those who believe that it romanticizes domestic violence. The first portion of the narrative follows the swoony courtship of Ryle and Lily; the story also blames his abusive tendencies on his traumatic past. Others have taken issue with the way that the novel is framed, shelved in the romance section of bookstores or marketed as a love triangle story. (A hastily scrapped coloring book version of It Ends With Us didn’t help matters.)

“I don’t expect everyone to like my books, so if someone doesn’t, it isn’t my job to deal with them,” Hoover told Glamour in February 2022. “That is their right, and I respect that. I put 100% of the focus into the people who do enjoy my books, and I do my very best to make those people happy.”

Despite—or perhaps because of—the discourse, those involved with the “very faithful” adaptation of Hoover’s book relied on fan input to try to get the movie right. Screenwriter Christy Hall told Entertainment Weekly that “20 mega-fans that had to sign an NDA” were given access to an early draft of the script, where they weighed in on proposed changes—and even convinced Hall to put an iconic line back in the movie. Here, a guide to some of the most notable changes from page to screen.

In the book, Lily is 23 and Ryle is 30—significantly younger than Lively, 36, and Baldoni, 40. Hoover told Today that when she wrote the novel, the new adult genre was particularly popular. So she made her characters young—though she wishes now that she hadn’t gone quite that young. “As an author, we make mistakes,” she said. “There’s no 28-year-old neurosurgeons, you know? You go to school for 15 years. And so to make corrections to what I messed up in the book, we aged the characters up somewhat.”

In the same interview, Hoover addressed some of Lily’s more outlandish costumes, a few of which came from Lively’s own closet. “You’ve seen a couple of outfits that are completely out of context,” the author said of early set photos. “I’m not worried about it.” She continued, “When I wrote the book, it wasn’t about the age of the characters. It wasn’t about what they were wearing. I don’t even think I described any clothing in the book. It was about the message that I wanted to get across.”

After years apart, Lily reconnects with Atlas when she dines at his restaurant. In the book, the establishment is called Bib’s, an acronym for “Better in Boston.” In the film, it’s called Root—a name that, like Bib’s, pays homage to a major moment from Atlas and Lily’s adolescent romance. “It stood for something in the book that became a big thing for Lily to show how much she meant to him,” Hoover explained to E! News. “So that changed to Root in the movie, because we didn’t have as much time to put in all of the things that happened in the book”—like Atlas giving Lily a refrigerator magnet that reads “better in Boston” before he moves to the city and away from her. But according to Hoover, “changing it to Root went back to a conversation they had as kids in the film [from which] you get the same feels that you got in the book.”

“I’m an unreliable narrator,” Lily says in her rooftop meet-cute with Ryle, which Lively’s husband Ryan Reynolds apparently had a hand in writing. That disclosure comes to bear once Ryle becomes violent towards Lily—first pushing her out of the way of a hot stove, then shoving her down a flight of stairs, before assaulting and attempting to rape her during another argument about Atlas. Camera angles and editing choices initially present these scenes as purposefully ambiguous—with Lily excusing the first two bouts of violence as mere accidents. It is not until later in the film, once Lily herself comes to terms with the true nature of their relationship, that the abuse is shown again in its full context.

But in the book, both readers and Lily herself acknowledge Ryle’s violence from the start. The first time Ryle physically assaults Lily in the kitchen, Hoover writes from her heroine’s POV: “So much gravity, pushing down on my emotions. Everything shatters. My tears, my heart, my laughter, my soul. Shattered like broken glass, raining down around me.”

The film adaptation of It Ends With Us scraps Lily’s flower shop employees outside of her sister-in-law, Allysa (Jenny Slate), including Lucy, Lily’s former roommate, and Devin, a gay character who exists solely to pose as Lily’s date to a party in order to make Ryle jealous. Another major character who is wisely cut from the movie? Ellen DeGeneres—yes, really. She is a full-fledged character in the book, at least in the eyes of SparkNotes.

In Hoover’s novel, a young Lily (played by Isabela Ferrer in the movie) and Atlas (Alex Neustaedter) fall in love while watching Ellen and Finding Nemo after school. DeGeneres is such a comforting figure in Lily’s life that she addresses entries in her childhood diary to the comedian, and later gives her daughter the middle name Dory, after DeGeneres’s forgetful animated fish. Atlas is equally enamored—at one point, he gives Lily a signed copy of DeGeneres’s memoir as a sign of his love and tells her upon rekindling their romance: “You can stop swimming now, Lily. We finally reached the shore.”

It was shrewd to cut this whole subplot, strange and superfluous as it is—not to mention the fact that the toxic workplace allegations that have emerged against DeGeneres since the book’s publication have chipped away at the comedian’s feel-good effect. But the movie still nods to this element of the novel: In one scene, Atlas and Lily watch Ellen together while speaking about the future, and a stuffed Finding Nemo toy can be spotted in her daughter’s nursery.

In both the novel and film, Lily tells Ryle she plans to divorce him while he cradles their newborn daughter, Emerson—named for the older brother that Ryle accidentally shot and killed while playing with a gun as children. They agree that if their daughter were ever in the same situation as Ryle has placed Lily, he would also want her to leave her partner. The movie also ends with a domestic violence resource hotline. Lily and Ryle’s rocky relationship as co-parents (an arrangement some have also criticized) plays out in Hoover’s 2022 sequel, It Starts With Us.

But according to screenwriter Christy Hall, the moment in the hospital after Ryle leaves—when Lily tells her daughter, “It ends with us”—was originally omitted from the script. “As a screenwriter, a big no-no is you don’t want any character to ever say the title of the film,” Hall told Entertainment Weekly. (The Idea of You would beg to differ.) “So in my initial draft…I had her say the line, ‘It stops here, between you and me,’ blah, blah, blah. I didn’t have her say, ‘It ends with us.’”

The group of fans invited to read the early draft were unanimously opposed. “That was a really funny moment,” said Hall, “because sometimes they’d be split on things, but that one was resounding, 100 percent out of 100 percent were like, ‘How dare you?!’’ and I was like, ‘I’m so sorry. I must be absolved of this sin.’”