Spoilers ahead for We Were Liars (obviously).

Now and then, a story comes along with an ending so heavy that it weighs you down for a little while. Like, you finish, and you physically can’t move for a bit because the ending knocked you out so hard. For me, that was the case when I finished the book We Were Liars by E. Lockhart. It’s got a walloping twist ending, and the new Amazon Prime Video series based on it is just as harrowing.

E. Lockhart herself was involved in the TV series, and she even wrote the big season 1 finale episode. “I wrote the finale, and that was a great chance to basically write a different version of the story that I had already written,” she said to TVLine. “I wrote a television version, and even though the same basic thing happens, it’s paced differently. The action is built out, the drama is heightened, the reveals are done in a different way — and there are some additional reveals that aren’t in the book.”

So whether you want to find out what happens without sitting through all eight episodes, or you just want to wallow together in the heaviness of the ending, you’ve come to the right place. Let’s dig into the ending of We Were Liars, including the major twist and the new parts that were changed from the book.

We Were Liars Ending Explained

What is We Were Liars about?

We Were Liars tells the story of Cadence “Cady” Sinclair Eastman, who’s spent every summer of her life on the fictional New England island of Beechwood. A bunch of family and friends all gather there each year, and the four oldest kids — Cadence, Johnny, Mirren, and Gat — become known as “the Liars.” The show picks up with Summer 17 on Beechwood after Cady ended Summer 16 with a head injury and selective amnesia. She spends the season trying to piece together exactly what happened last year.

What is the twist at the end of We Were Liars?

It all comes together for Cady (and the audience) in the season finale when she remembers that her grandfather’s mansion, Clairmont, is being rebuilt because she and the other Liars burned it down last summer. They’d uncovered a lot of family secrets and plots to control the inheritance. So, they decided to try to teach the older generation a lesson by burning it all down. But, it didn’t go exactly according to plan.

First, the Liars forgot about the family dogs locked inside. I don’t know if there’s anything more horrible than watching innocent animals suffer. But We Were Liars subjects us to that when Cady is unable to save the trapped dogs from the fire.

Meanwhile, Johnny and Mirren got trapped on the higher floors of the house, and Gat ran back inside when he didn’t see Cady right away. When Cady finally made it to the boardwalk, she realized none of the other Liars were there to meet her. And that’s when a gas main exploded, and the house was engulfed.

Here’s where the big twist comes in. When the explosion happened, Cady was thrown back and suffered her head injury, while the other three Liars were all trapped inside and died. We learn that even though it seems like Cady’s been talking to the Liars all summer, she was actually interacting with their ghosts; she’s the only one left alive.

Once Cady uncovers the truth, she talks to her grandfather, Harris. Even though the rest of the world thinks the fire happened because of faulty wiring, he knows the truth. He threatens to reveal the truth unless she takes her place as the next in line to inherit the Sinclair family fortune. But, in the end, Cady decides to venture out on her own, saying she’s “just really not into fairytales anymore.

How is the We Were Liars TV show different from the book?

The TV series contains one more twist that the book doesn’t. At the very end, there’s a scene of Carrie getting ready to leave Beechwood for the summer. But she finds her son Johnny waiting for her. She tells him she thought he’d “left” by now, and he responds, “I don’t think I can.”

It’s a moment that doesn’t happen in the book, but it does seem to set things up for a possible season 2. Amazon Prime Video also has the rights to the prequel book Family Of Liars, which delves into Carrie’s story, so perhaps this extra twist is hinting at an additional story.