This article contains spoilers for We Were Liars.E. Lockhart’s We Were Liars is the latest young adult literary phenomenon to receive the book-to-screen treatment. Unpacking the scintillating mysteries of the wealthy Sinclair family and a darkly fateful summer on their private island, this new thriller series premiered on June 18, 2025. Giving teen drama, Succession-style family politics, and murder-mystery all at once, We Were Liars already has the internet on fire discussing the shocking ending (no pun intended). However, as is to be expected, various parts of We Were Liars, including its twisty ending, were changed when the material was adapted to the screen. Here are all the major differences between Lockhart’s original source material and the new teen series, which is now streaming on Prime Video.
What Happens in ‘We Were Liars’?

In order to highlight all the variations between book and show, we first need to briefly outline what exactly goes down over the course of eight episodes and 320 pages of We Were Liars. Our protagonist is 16-year-old Cadence Sinclair Eastman (Emily Alyn Lind), the eldest grandchild of and heir to the fortune of her grandfather, Harris Sinclair (David Morse). Cadence is one of many siblings and cousins within the vastly wealthy Sinclair family, a proper American dynasty. Every summer, Cadence and her family spend time at their private, idyllic (fictional) island called Beechwood off of Martha’s Vineyard. There, Cadence primarily hangs out with the other older cousins that are her age —​​​​​​​ Johnny (Joseph Zada) and Mirren (Esther McGregor) — and their honorary cousin, Gat (Shubham Maheshwari), who Cadence begins an on-and-off summer romance with at the end of “Summer 8” (as she labels each vacation). This group refers to themselves as “The Liars,” and they look forward to coming to the island together more than anything every year.

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However, at the beginning of the series, we immediately learn that Cadence, having washed up on the shore, is suffering severe memory loss for an unknown reason. Cadence returns to Beechwood for “Summer 17,” determined to find out what she does not remember about last summer on the island. Cadence’s mother makes everyone swear to let Cadence figure it out in her own time, and over the course of the series, she attempts to digest the truth and piece it together by talking to her family and fellow Liars. Essentially, Cadence and the Liars, following eight episodes and 320 pages of familial drama, determine that it is in everyone’s best interest to burn down the Beechwood house. However, this goes horribly awry, and all the Liars except for Cadence are killed in the fire. All season, any conversations she had with Gat, Johnny, or Mirren were simply ghosts from her past haunting her.
The Show Spans Less Time

Prime Video

Compared to the book, the timeline of Prime’s adaptation of We Were Liars is consolidated quite a bit. In the book, the main events of the story span from the death of Grandma Tipper in Summer 14 to Cadence returning in Summer 17. The fire itself takes place in Summer 15, then Cadence takes two summers to recuperate, spending time with her father in Europe and nursing her wounds. However, in the We Were Liars TV series, the entire plot takes place over the course of Summer 16 and 17.
Deeper and Different Characters

Prime Video

There are characters in the We Were Liars novel that are cut from the show entirely, such as Mirren’s younger brother Taft. Beyond that, all the characters’ motivations and qualities are altered or deepened in ways that were not in the original text.

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For example, Johnny is explicitly gay in the show, whereas it was only implied in the novel. Mirren’s romance with Ebon and Gat’s family is actualized in scenes, as opposed to the book, where they are only mentioned. The Sinclair family members, particularly each of the matriarchs, are expanded upon as characters, providing more context for the story’s ultimate twist (the 2022 prequel novel Family of Liars lends some of the juicy details here).
A (Slightly) Changed Ending

Prime Video

While the nature of the ending in both versions is the same, the ending of the We Were Liars series differs a little from the book. The major difference is that, in the book, the deaths that occur in the fire (Johnny, Mirren, Gat, and the dogs, which everyone brushes over, but they should not) are the direct result of errors made by Cadence. She used too much gasoline, and the fire raged faster than expected, and because Cadence started the fire on the wrong side of the house, it was impossible for the Liars to escape. The amnesia she suffers is not only due to her trauma, but her guilt. In the show, inversely, all the Liars share some responsibility for the unexpected severity of their fire and the inability to exit. Cadence tries to save the dogs (there we go), and each of the other Liars ends up inside the house during the inferno for their own missions. Cadence is thrown into the water, which causes her to hit her head and wash up on the shore. While in the book it is implied that her family members may know the fire was her fault, they explicitly know in the show. They have simply agreed to let Cadence come to terms with the truth in her own time. Harris absolutely knows, as at the end of the series, he tells Cadence that he wishes to make her his fortune, on the condition that she never reveals the secret of what happened at Beechwood. We never get to find out Cadence’s response to this proposition, implying that Prime may be revving up for a titillating We Were Liars Season 2.

We Were Liars

Release Date

June 18, 2025

Network

Prime Video

Directors

Nzingha Stewart

Writers

E. Lockhart