Finding the right faces for a John Green adaptation is always a high-stakes gamble. Fans are protective. They’ve lived inside the protagonist’s head for years. When Max (formerly HBO Max) finally released the movie, the conversation immediately shifted from "will they ruin it?" to how the cast of Turtles All the Way Down film managed to handle such heavy, internal material without making it feel like a cheesy PSA.
It’s a weird story if you think about it. You’ve got a teenage girl, Aza Holmes, who isn't just "sad" or "anxious" in a movie way. She’s trapped in thought spirals about C. diff and human microbiota. Then you add a missing billionaire, a massive windfall of cash, and a budding romance with the billionaire’s son. It could have been a disaster. Honestly, the only reason it works is the chemistry between the leads.
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Isabela Merced as Aza Holmes
Isabela Merced had a massive mountain to climb. How do you play someone whose biggest struggles are happening silently inside their own brain? In the book, we get pages of internal monologue. On screen, Merced has to show that "tightening" through her eyes and her hands.
You might remember her from Dora and the Lost City of Gold or Sicario: Day of the Soldado, but this is different. It’s raw. She portrays Aza’s OCD not as a quirk, but as an exhausting, full-time job. There’s this specific scene where she’s trying to enjoy a moment with Davis, but you can see the panic rising because she’s thinking about the exchange of bacteria during a kiss. It’s painful to watch. That’s the point. Merced brings a level of empathy to the role that makes you want to reach through the screen and tell her it's going to be okay, even though, as the movie teaches us, "okay" looks different for everyone.
Cree as Daisy Ramirez
Every Aza needs a Daisy. Cree Cicchino plays Aza’s best friend, and she is basically the engine of the movie’s energy. While Aza is internal and cautious, Daisy is loud, writes Star Wars fanfiction, and is desperate to escape her "broke" reality.
The dynamic between Merced and Cicchino is the heartbeat of the cast of Turtles All the Way Down film. They feel like real friends who have been through the trenches together. They fight. They say mean things. They apologize. Cicchino avoids the "sassy best friend" trope by showing the genuine frustration of loving someone whose mental illness takes up all the oxygen in the room. It’s a nuanced performance that acknowledges that being a caregiver or a best friend to someone with OCD is actually really hard.
Felix Mallard as Davis Pickett
Then there’s Davis. Felix Mallard, who a lot of people recognize from Ginny & Georgia, plays the "rich kid with a missing dad." It would have been so easy to make Davis a cardboard cutout of a love interest. Instead, Mallard plays him with this quiet, observant loneliness.
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Davis is more than just a billionaire’s son; he’s a kid who loves astronomy and feels just as trapped as Aza, though his cage is made of gold and lawyers. The chemistry between Mallard and Merced is flickering and hesitant. It doesn’t feel like a typical Hollywood romance where love cures everything. They both know they're broken in different ways. Their relationship is more about finding someone who is "quietly there" rather than someone who "fixes" you.
The Supporting Players Who Ground the Story
You can’t talk about the cast of Turtles All the Way Down film without mentioning Judy Reyes. She plays Aza’s mom. If you grew up watching Scrubs, you know she can do "concerned but tough" better than anyone. As a widowed mother and a nurse, she is constantly hovering, not out of malice, but out of a terrifying love. She knows she can't reach the places Aza goes in her head, and Reyes plays that helplessness with such dignity.
Then there is Maliq Johnson as Mychal. He’s the artistic, slightly awkward friend who dates Daisy. His presence adds a much-needed layer of normalcy to the group. He’s not part of the missing billionaire mystery. He’s just a guy trying to make art and navigate high school.
- Director: Hannah Marks. She’s an actor herself, which usually means she knows how to talk to her cast to get those small, intimate beats.
- The Author: John Green was heavily involved, ensuring the spirit of the 2017 novel stayed intact.
- The Script: Written by Elizabeth Berger and Isaac Aptaker, the duo behind Love, Simon.
Why the Casting Choices Matter for OCD Representation
Representation is a buzzword, sure. But for the OCD community, the cast of Turtles All the Way Down film represents a shift. Most movies treat OCD as a cleaning habit or a "cute" organizational trait. This film doesn't do that. Because Isabela Merced plays it so straight, we see the "thought spirals" for what they are: a medical condition.
The casting of a Latina lead for Aza also subtly changes the landscape of the story without making it "about" her ethnicity. It’s just Aza. She’s a girl in Indianapolis dealing with a terrifying mental health crisis, and she happens to look like Isabela Merced. This inclusivity feels natural rather than forced, which is exactly how good casting should work.
The film handles the "mystery" of Russell Pickett (Davis's dad) as a secondary plot, which was a smart move. If the actors had leaned too hard into the detective side of the story, the emotional weight of Aza’s journey would have been lost. Instead, the cast keeps the focus on the relationships. Even the brief appearances by the Pickett's lawyer or the younger brother, Noah, serve to highlight how isolated Davis and Aza feel.
Final Perspective on the Ensemble
The cast of Turtles All the Way Down film succeeds because they don't try to make the characters "likable" in every scene. They allow them to be selfish. They allow them to be scared. Aza is often a difficult friend. Daisy is often a self-centered one. By leaning into those flaws, the actors make the story feel like a memory of high school rather than a polished product.
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If you are looking to dive deeper into how this story came to life, your next steps should be grounded in the source material and the real-world context of the production.
- Watch the Behind-the-Scenes Interviews: Search for the "Cast Chemistry" featurettes on Max. Seeing Merced and Cicchino interact out of character proves their on-screen bond wasn't just good acting—they actually get along.
- Compare the Book's Internal Monologue: If you’ve only seen the movie, read the first three chapters of John Green's novel. It will give you a massive appreciation for how Merced translated those complex thoughts into physical acting.
- Research the Scientific Accuracy: Look into the work of Dr. Elena Eichman, who consulted on the film to ensure the "thought spiral" sequences were clinically accurate to the experience of intrusive thoughts.
- Check Out the Soundtrack: The music heavily influences how the cast's performances land. The inclusion of artists like Sylvan Esso and even the Star Wars references in the dialogue ground the performances in a specific, modern reality.
The film is a rare example of a YA adaptation that treats its audience, and its characters, like adults. The cast didn't just show up and say the lines; they inhabited a very specific, very painful world and made it beautiful.