Auden's Summer Plans

Auden's choice to stay with her dad, Robert, and step-mom, Heidi, for the summer is met with derision by her mother Victoria, a respected English professor. In the movie, Auden has already made this decision and is driving to Colby a few minutes after the opening credits. In the novel, it's a more drawn-out process, with Auden deciding to take Heidi up on her offer after spending a few lonely weeks at home.

Similarly, Auden doesn't plan to start working at Heidi's boutique, Clementine's, until she's in Colby and sees how an overwhelmed Heidi is trying to balance the financial side of the business with taking care of her newborn. On-screen, all these decisions have already been made.

Auden's Introduction to Eli

Auden and Eli immediately form a bond based on their insomnia-fuelled sleep schedules — they're both "nocturnes," as Eli calls it in the movie — so it makes sense that they meet late at night on the deserted boardwalk. Auden notices Eli riding his bike night after night, but they don't talk until he veers too close to her, makes her knock over her coffee, and offers to buy her a fresh cup. In the book, Auden runs into Eli while taking her colicky step-sister, Thisbe, out for a walk at sunrise in hopes of soothing her to sleep.

Auden's Brother (or Lack Thereof)

It's clear that Auden feels older than her years — and that her parents expect that of her. In the adaptation, it's implied that this is a side-effect of Auden's parents' divorce when she was a young child. In the book, though, there's a secondary reason: Auden's free-spirited older brother, Hollis, who's aimlessly travelling abroad for most of the novel. His tendency to shirk responsibility and act out, especially when they were children, forced Auden to be more of a "little adult," she explains in the book.

Hollis's gift of a tacky picture frame, featuring the words "The Best of Times," is partially what convinces Auden to take the leap and spend the summer in Colby; she realises she doesn't know what to put in the frame, because she hasn't had any experiences that fit the label. While Hollis didn't make the movie cut, the picture frame does get a cameo at the end of the film.

Victoria's Storyline

Auden's mother, Victoria, is a haughty English professor with high expectations for her daughter and a habit of looking down on anything that threatens their connection, like Auden's dad, step-mom, and her summer in Colby. In the movie, Victoria's character development mostly happens off-screen. She's snooty and judgmental when she visits Auden at the boutique but quickly comes to the rescue when Heidi crumbles under the pressure of new motherhood, encourageing her to stand up to Robert and giving tips on taking care of Thisbe.

In the book, Victoria shows up to help at the very end, but only after Eli's mom, Karen, helps with Thisbe and encourages the initial "intervention" with Heidi and Robert. Victoria is also in a somewhat covert relationship with one of her grad students, a fact that shakes Auden's perspective of her mother when she finds out.

Auden and Eli's First Kiss

After spending multiple nights together to fulfil Auden's "quest" of experiencing the childhood and teenage activities she never had, Auden and Eli can no longer ignore their chemistry and finally (finally!) go in for the kiss. In the Netflix version, it happens after a "hot dog party" and food fight, when Auden, Eli, and their friends run into the ocean for a night swim (very efficiently knocking three items off of Auden's quest list). They kiss with the waves crashing around them and their friends cheering in the background — very sweet and appropriately cinematic.

In the book, Auden and Eli's first kiss happens on a crowded dance floor at the Tallyho, a local club that Eli sneaks them into. Tallyho is a running joke in both the book and the film, but we don't get to see it brought to life on-screen. (Auden's friend Leah, the biggest — and possibly only — Tallyho fan in either version, would be offended.)

Auden and Eli's Third-Act Split

Just when their connection starts blooming into something more, Auden and Eli hit a rough patch. In the film, it happens the morning after their first kiss. Auden is running to get them coffee when she finds Robert sitting at the coffee shop, bags packed, getting ready to separate from Heidi for a while. This kicks up Auden's lingering pain and guilt from her parents' divorce and she rejects Eli's gift of a bike and offer to teach her to ride it. Embarrassed and defencive, Auden begins to question why Eli won't open up to her about his friend Abe's recent death. The argument gets ugly, with Auden accusing Eli of using her as a "do-over" after Abe.

Their split in the book happens more quietly. Several days after their first kiss, Auden overhears Robert and Heidi arguing while she and Eli are delivering newspapers (again, for the quest). Though shaken, she tells Eli what happened and stays the night with him at his apartment, with both insomniacs manageing to fall asleep together. The next morning, Auden runs into her dad while he's leaving the house, preparing to move out for a while, and she starts to slip back into her shell. She skips a kickball game that Eli organises that night, not telling anyone why, and then runs into her high school classmate Jason, her would-be prom date who stood her up for a school commitment. Scared by the turn of events with Robert and Heidi, Auden quietly disappears into her old habits, texting Jason, staying home at night to study, and avoiding Eli and her new friends.

Eli's Return to BMX

Not long after Auden and Eli's argument, Auden's friend Maggie calls Auden with the surprise news that Eli is about to compete in a BMX contest. Auden rushes to the park in time to watch, and afterwards, takes him aside so they can clear the air. Later, it's revealed that Eli is coming out of retirement and he ultimately moves to Barcelona to fulfil a longtime dream and start seriously competing. This differs from the book, where Auden never watches Eli compete in person — she only finds out that he's riding publicly again from a video she watches with Maggie and their other friends Esther and Leah. That, along with her newfound anger at Robert for leaving Heidi, is what inspires her to approach Maggie about learning how to ride a bike.

The "Prom"

After they reconcile, Eli has the idea to recreate the prom experience that Auden missed out on. He convinces her to put on her never-worn prom dress and takes her to the beach, where their friends surprise her with a "beach bash"-themed prom under the pier.

It's a flipped version of what happens in the book, in which Heidi is planning Colby's annual Beach Bash on the boardwalk and decides to make it prom-themed. Jason asks Auden to go as an apology for ditching her at their real prom, but after he stands her up again (unbelievable), Auden asks Eli. He says no without an explanation and Auden plans to stay home and take care of Thisbe. When her mom shows up to help, she bikes down to the boardwalk and runs into Eli, who tells her he turned her down to compete in one final BMX contest. He offers her a ride to the boardwalk but she hops back on her bike and tells him she'll meet him there. In the book, Eli also retires after this last contest and starts taking classes at the U, allowing the couple to stay close to each other; at the end of the movie, in comparison, they're in a long-distance relationship.