‘Thornbird’ book: 5 essential facts on Kennedy’s chilling hit

The “Thornbird” book, Elle Kennedy’s first young adult thriller, is headed to the screen. Hulu is developing a series based on the novel with “Pretty Little Liars” creator I. Marlene King, Deadline reported Sept. 30. Here are 5 things to know about the book before the show takes shape.

We covered the deal itself in our report on the Thornbird TV adaptation. This guide focuses on the novel.

1. The “Thornbird” book is Kennedy’s YA debut

Delacorte Press published “Thornbird” June 30. It is Kennedy’s first young adult novel and the first book she has released under the pen name E. Kennedy. The hardcover runs 448 pages and is aimed at readers 14 and up, according to the publisher’s listing on Bookshop.

It opened on The New York Times best-seller list, Deadline reported. The Thornbird book reached U.K. shelves July 2, according to Paste Magazine. The publisher pitches it as a race by Ryan “to solve the crimes of her family’s twisted past” before time runs out.

2. The plot centers on a serial killer’s daughter

Ten years after her father, the infamous serial killer Gabriel Thorn, was caught, 17-year-old Ryan Shipley returns to Starling, Tennessee, and tries to keep her real identity hidden. As others reopen the case, “cryptic texts, eerie coincidences, and a chilling note” leave the town wondering what she knows, the publisher’s description says.

Kirkus Reviews says Ryan, born Gabrielle Thorn, comes back after her grandmother’s death and builds a fake backstory while the community is still scarred by her father’s crimes.

3. Critics found it creepy, with a few caveats

Kirkus called the novel “a largely satisfying mystery that’s appealingly creepy and dark.” The review praised the slow reveal of Ryan’s disturbing memories of her father and a romantic subplot involving 2 classmates. It also said the central premise strains belief and that the twist, while well executed, can be guessed.

4. True crime shaped the story

In a cover-reveal Q&A with Paste Magazine in October 2025, Kennedy said a young narrator suited the material. “YA naturally felt like the right fit because I wanted to explore coming-of-age and identity themes,” she said. She also cited her love of true crime and thrillers, naming Stephen King and Ann Rule as influences. Rule, a longtime true-crime writer, is best known for “The Stranger Beside Me,” her book about Ted Bundy, a subject that echoes the Thornbird book’s focus on a killer’s family.

5. The “Thornbird” book follows a hit screen run

Kennedy grew up in the suburbs of Toronto and has written more than 50 contemporary fiction and romance novels, landing on The New York Times, USA Today and Wall Street Journal best-seller lists, according to her official bio. Her “Off Campus” series became a Prime Video show that premiered in May and drew 36 million viewers worldwide in its first 12 days, making it Prime Video’s third most-watched debut series ever, according to Deadline. Season 2 is in production, and her novel “Girl Abroad” is in development at Amazon with A24 Television.

King will write and executive produce the “Thornbird” series through 20th Television, with Kennedy and Lauren Wagner also executive producing, Deadline reported. King created Freeform’s “Pretty Little Liars,” based on Sara Shepard’s books. The project is in early development, so there is no cast or premiere date yet. Deadline described the planned series as a coming-of-age thriller about “a girl at the center of her own true-crime mystery.” That means readers who pick up the Thornbird book now will know the twists well before any episodes arrive.

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