Suzy reveals she has stopped speaking to others unless necessary, one month after the death of her close friend.

Suzy's mother breaks the news that Franny drowned while swimming in the ocean during a summer vacation in Maryland.

At the aquarium exhibit, Suzy reads about the Irukandji jellyfish and forms the hypothesis that one may have stung Franny.

At age five, Suzy and Franny meet at swim lessons and instantly bond when Franny swims underwater and Suzy follows.

Suzy and both divorced parents attend the first appointment with child psychologist Dr. Legler, who hears their concerns about Suzy.

During a weekly dinner with her father at Ming Palace restaurant, Suzy stops answering questions and commits fully to not-talking.

After rejecting several candidates, Suzy identifies Australian jellyfish expert Jamie Seymour as the one person who can confirm her theory.

In sixth grade, Franny calls Suzy 'weird' in front of her new friends at the lunch table and storms away.

Suzy delivers her jellyfish science report, but classmates mock her and several begin calling her 'Medusa' after class.

On the last morning of sixth grade, Suzy pushes frozen disks of her own urine through the slats of Franny's locker.

Franny discovers her urine-soaked belongings, begins to cry, and walks down the hallway without ever making eye contact with Suzy.

Suzy attends Franny's funeral unable to cry, feeling angry at the large crowd of mourners she does not recognize.

Suzy uses her father's stolen credit card information to purchase an airline ticket to Cairns, Australia, to find Jamie Seymour.

The airline gate agent stops Suzy at check-in, explaining that children are not permitted to fly internationally without an adult.

At the airport, Suzy's family arrives and she watches a TV broadcast of Diana Nyad's successful swim, feeling ready to move forward.

Seventh grader Suzy Swanson stops speaking after learning her former best friend Franny Jackson drowned in the ocean, unable to accept that it was simply a senseless accident. Convinced that an Irukandji jellyfish sting was responsible, Suzy identifies Australian expert Jamie Seymour as the one person who can confirm her theory. Interspersed flashbacks reveal the painful unraveling of her sixth grade friendship with Franny, culminating in a failed attempt to send a desperate message on the last day of school. Back in real time, Suzy's jellyfish science report fails to reach her classmates, and she secretly plots to fly to Australia and meet Jamie in person. After stealing money and credit card information from her family, Suzy arrives at the airport only to be turned away because children cannot travel internationally alone. Watching Diana Nyad's successful swim broadcast nearby, Suzy finds the inspiration she needs to accept Franny's loss and begin moving forward.

The core events of Suzy's quest to understand Franny's death

In the Prologue, Suzy compares jellyfish movement to a beating heart and notes that Franny's heart beat far fewer times than most.

At the aquarium, Suzy wanders alone to the jellyfish exhibit and realizes afterward that no one in her class noticed she was gone.

After the aquarium trip, Suzy counts the four to five jellyfish stings occurring somewhere around the world during every passing second.

Suzy's brother Aaron visits with his boyfriend Rocco and tells Suzy that middle school is hard but survivable.

Suzy writes out a list of jellyfish facts and statistics and formally labels her idea about Franny's death as her hypothesis.

Suzy researches jellyfish scientist Dhugal Lindsay as a possible expert but rejects him because he also writes jellyfish haiku.

Mrs. Turton shows the class a photo of Earth taken from billions of miles away, and Suzy feels panicked by humanity's smallness.

In a fourth grade memory, Suzy and Franny give each other nicknames — Mizz Frizz and Strawberry Girl — cementing their closeness.

Suzy researches long-distance swimmer Diana Nyad and biochemist Angel Yanagihara as potential jellyfish experts before moving on to find a better candidate.

Suzy watches a video of Jamie Seymour writhing in pain during a two-day hospital stay after an Irukandji jellyfish sting.

Late one night, Suzy calls Jamie's research center in Australia but cannot bring herself to say a single word when someone answers.

At the sixth grade campout, Dylan Parker slams a frog against a tree to impress Franny, and Franny does nothing to stop him.

After Suzy's science presentation, Justin leaves jellyfish sketches on her desk, and Mrs. Turton awards Suzy an A and invites her to lunch.

Suzy and Justin watch a nature video together in Mrs. Turton's classroom at lunch and walk to their next class in shared silence.

The day before her planned flight, Suzy visits Aaron and Rocco's apartment and accidentally locks the spare key inside when she leaves.

From the Prologue onward, Suzy's deep scientific mind and emotional sensitivity color every experience in her seventh grade year. Her careful research into multiple jellyfish experts, her obsessive counting of worldwide stings, and her failed attempt to call Jamie's research center in Australia reveal the relentless dedication behind her quest. Flashback memories show the warmth of her friendship with Franny — including the nicknames they gave each other — alongside sixth grade cruelties like Dylan Parker killing a frog at the campout. In real time, quiet connections form around Suzy despite her silence, as classmate Justin Maloney sketches jellyfish during her report and later shares a peaceful lunch and a nature video with her. Meanwhile, Mrs. Turton gives Suzy an A and a safe place to eat, while Suzy's methodical theft of money and her accidental locking of Aaron's apartment key foreshadow the unraveling of her Australia plan. These secondary events enrich the emotional landscape of the novel, showing the costs and small consolations of Suzy's grief-driven mission.

The supporting moments that shape Suzy's world and investigation

At age seven, Suzy comforts Franny after classmate Aubrey LaValley tells Franny she is neither pretty nor smart.

In science class, Suzy is assigned Justin Maloney as a lab partner and tells Mrs. Turton her research report topic is jellyfish.

In fourth grade, Franny asks Suzy to promise to send a big, clear secret signal if Franny ever acts like Aubrey LaValley.

On a fifth grade bus ride, Suzy tries to tell Franny about her parents' divorce but cannot when Franny only wants to discuss boys.

In fifth grade, Franny tries to tame Suzy's frizzy hair with styling products, but Suzy washes them out as soon as Franny leaves.

Dr. Legler tells Suzy that anyone with something truly important to communicate should say it directly and face-to-face.

Suzy rides her bike to Franny's house to apologize and start over, but Franny is outside with other girls and ignores her.

At the sixth grade campout, a teacher publicly mocks Suzy's answer that the surrounding night sounds are like an orchestra.

Suzy freezes her own urine in plastic containers and arrives at school before anyone else to carry out her plan for Franny.

On the same day Franny walks away from her soaked locker, Suzy gets her first menstrual period and sees it as an accusation.

Suzy wakes from a dream about swimming toward Jamie through jellyfish and decides that staying still is worse than being stung.

At a counseling appointment, Suzy asks Dr. Legler how a person says goodbye, but the doctor completely misunderstands what Suzy is really asking.

The morning of her planned flight, Suzy snaps at her mother and tells her to leave, saying the opposite of what she wants.

Suzy calls Franny's mother before leaving home and is shocked to learn that Franny always admired Suzy and wanted to be more like her.

Suzy arrives at the school dance in a plain everyday costume and goes inside with Sarah Johnston to join Justin and other classmates.

The key turning points in Suzy's story begin long before Franny's death, rooted in a promise made in fourth grade to always send a signal if something went wrong between them. In fifth grade, Suzy's failure to confide in Franny about her parents' divorce marks the first quiet fracture in their friendship, while growing differences in their interests and style drive them steadily apart. The humiliation at the campout and the desperate bike ride to Franny's house show how far things have deteriorated before the urine incident — and how little Suzy understood what that act would actually mean. A jarring revelation about her first period arrives the same day she realizes the message was an ending rather than a new beginning, compounding her guilt. The story's emotional resolution arrives through a dream that moves Suzy to action, a misread goodbye at the counselor's office, and a shocking phone call to Franny's mother, before Suzy finally steps into the school dance alongside new friends.