The road-trip movie isn't kidding around with the warning it kicks off with.

Warning: This story contains spoilers for Don't Make Me Go.

"You're not going to like the way this story ends" is how Wally (Mia Isaac) opens Don't Make Me Go, and she is not wrong.

While watching her father Max (John Cho) finally share his secret love of music with her at karaoke, teenaged Wally suddenly dies. It's revealed that she had hypertrophic cardiomyopathy, a genetic heart condition that's often hard to detect. In voiceover, Wally walks the audience through the signs, including her "stress sweat" and thinking the boy she liked was the reason her heart was racing. We then see Max and their loved ones heartbroken at Wally's funeral; even her estranged mother makes an appearance. 

For most of its running time, Don't Make Me Go is about a single dad and his daughter going on a road trip. As it happens, Max is hiding a rough health prognosis of his own: bone cancer. He's been given a year to live. So he takes his daughter on a journey in an attempt to teach her everything he thinks she'll need to learn from him before he dies. 

The shocker twist ending was always the plan screenwriter Vera Herbert had for the movie. Viewers are fixated on Max telling Wally the truth, and elated when she gets him to agree to surgery. Then the rug is pulled out from under them. "That's a bit how life works in these moments," Herbert says.

Cho's confident karaoke turn was another piece of the puzzle. "I wanted to let them have a huge moment together where she sees her dad be a total rockstar," Herbert explains. 

Credit: Prime Video / Amazon

The screenwriter has had to stick to her convictions for nearly a decade. Back in 2012, Herbert's script was named one of the Black List's best unproduced screenplays under its original title A Story About My Father. But it wasn't until 2021 that Amazon Studios signed on to develop it.

"For me, it would be a perfectly valid movie that ends with everything ending up fine," she says. "But the story I want to tell is about how tragedy comes out of the left field, and you have to carry on anyway." 

Herbert's own father died unexpectedly when she was 18, and Don't Make Me Go came from her desire to tell a story that touched on their close relationship. Her screenplay ended up revising history by having the daughter die instead of the father, but still examined how much parents and their children can learn from one another. "With the ending, Max sees that he has learned things from his daughter in order to carry on without her," Herbert explains, "versus what he thought he was doing, which is teaching her how to live without him." (Actor Cho describes reading Herbert's ending as a "Keyser Söze moment.")

Before her sudden death, Wally convinces her father to get bone surgery, which turns out to be successful: At the very end of Don't Make Me Go, Max drives off with his girlfriend, Annie (Kaya Scodelario), hopefully to a richer life infused with the fearlessness of his deceased daughter.

"I always wanted the film to end with a feeling of hope that Max has gone through tragedy, but because of the love he shared with his daughter, he wants to live the full life he promised her he would," Herbert says. "He knows he needs to keep going, because that's what she wanted him to do."

Don't Make Me Go is now streaming on Amazon Prime Video.

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