The arrival of the sports comedy-drama Stick on Apple TV+ in June 2025 introduced audiences to a refreshing take on the classic golf underdog story. While Owen Wilson’s portrayal of the washed-up pro Pryce Cahill provides the comedic and emotional anchor, and Peter Dager’s Santi Wheeler offers the youthful prodigy narrative, it is the character of Zero who has undeniably stolen the spotlight. Played with a magnetic, sharp-edged intensity by Lilli Kay, Zero is far more than a supporting cast member; they are the catalyst for the show’s most profound shifts in tone and theme.

In the world of Stick, Zero (born Christina Marie Duffy) starts as a cynical bartender at the Sparling Meadows golf club but quickly evolves into the indispensable caddy and emotional confidant for Santi. Their presence disrupts the traditional "mentor-protege" dynamic, introducing a modern, anti-capitalist, and gender-fluid perspective into the often-stuffy atmosphere of professional golf.

Who Plays Zero in the Apple TV Series Stick?

The actor behind Zero is Lilli Kay, a rising star who has spent the last few years building a reputation for transformative performances in prestige television. Before taking on the role of the headstrong bartender-turned-caddy in Stick, Kay was perhaps best known for their work in the Paramount Network’s Yellowstone, where they played Clara Brewer, and Showtime’s Your Honor, where they portrayed Fia Baxter.

In Stick, Lilli Kay brings a specific kind of lived-in authenticity to Zero. The character is written as gender-fluid and unapologetic, a persona that mirrors Kay’s own public identity and advocacy for LGBTQ+ representation. This alignment between actor and role is palpable on screen; Kay inhabits Zero with a physical confidence and a verbal dexterity that makes the character feel like a fully realized human being from their very first scene in the third episode.

Kay’s performance is marked by a refusal to make Zero "palatable" for the sake of the other characters. Whether they are mocking the "golf bros" at the bar or challenging Pryce Cahill’s outdated coaching methods, Kay maintains a consistent edge that keeps the audience—and the other characters—on their toes.

The Identity and Personality of Zero Explained

To understand why Zero resonates so strongly with viewers, one must look at the layers of identity that Jason Keller and the writing team have woven into the character. Zero is introduced not just as a worker, but as a philosopher of sorts. They describe themselves as an anti-capitalist and a post-colonial feminist, labels that they don’t just wear as badges but live out through their actions.

Zero’s gender-fluidity is handled with a commendable lack of fanfare in the show. It is presented as a simple fact of their existence, which allows the narrative to focus on their competence and their complex emotional life rather than making their identity a "problem" to be solved. This approach feels modern and necessary in a 2025 television landscape.

Personality-wise, Zero is defined by a blend of vulnerability and defiance. They are fiercely independent, having navigated a difficult family background that is hinted at throughout the first season. This independence makes them the perfect foil for Santi Wheeler, who is often stifled by his mother’s expectations and Pryce’s professional ambitions. Zero represents a life lived outside the "lines," which is exactly what a rigid sport like golf—and a disciplined kid like Santi—needs to witness.

Zero's Evolution from Bartender to Caddy

The narrative trajectory of Zero in the first season of Stick is one of the show’s most compelling arcs. Their introduction in Episode 3, titled "Daddy Issues," serves as a turning point for the series. At this stage, Santi is struggling with the pressure of his first tournament and his burgeoning resentment toward Pryce. When Zero, a recently fired bartender, crosses paths with him, the chemistry is instantaneous.

By Episode 4, "Zero Sum Game," the shift becomes official. Pryce Cahill, realizing that he is losing his grip on Santi’s motivation, makes the desperate and unconventional choice to hire Zero as Santi’s caddy. This decision is born out of a realization that Santi will only listen to Zero.

The transition from pouring drinks to reading greens is not just a career change for Zero; it is a strategic entry into a world they fundamentally despise. Watching Zero navigate the country club environment—a bastion of the very capitalism they critique—provides some of the show’s best social commentary. They don't just carry the bag; they challenge the culture of the sport, forcing Santi to think about why he plays and for whom he is performing.

How Zero Impacts the Relationship Between Pryce Cahill and Santi

The core conflict of Stick is the tug-of-war for Santi Wheeler’s soul. On one side is Pryce Cahill (Owen Wilson), who views Santi as his "lottery ticket" back to relevance and redemption. On the other side is Zero, who views Santi as a person first and a golfer second.

Zero’s influence on Santi is a constant source of friction with Pryce. In the traditional golf movie trope, the coach is the ultimate authority. Stick subverts this by making the caddy the true spiritual guide. In Episode 5, "The Birdie Machine," we see Zero’s methods in action. While Pryce focuses on technical mechanics and historical stats, Zero focuses on Santi’s headspace, using their shared bond and Zero’s intuitive understanding of Santi’s anxiety to lead him to victory.

This creates a fascinating jealousy in Pryce. He is forced to acknowledge that his decades of professional experience are often less valuable than the emotional intelligence Zero brings to the bag. This dynamic forces Pryce into a rare state of introspection, as seen in the later episodes of the season, where he must reconcile his own past failures as a father and a player with the new reality Zero has created.

Key Moments and Spoilers for Zero in Stick Season 1

As the season progresses, Zero’s role deepens from a disruptive force to a central emotional pillar. Several key moments stand out:

  1. The First Meeting (Episode 3): After Santi walks off the course in frustration, Zero finds him. Instead of offering platitudes, they offer a blunt assessment of the "golf world" that immediately earns Santi's respect.
  2. The Hiring (Episode 4): The scene where Pryce offers Zero the caddy job is a masterclass in negotiation. Zero’s demand for a fair wage and their refusal to "bow down" to Pryce sets the power dynamic for the rest of the season.
  3. The Victory (Episode 5): When Santi wins the tournament with Zero on his bag, the celebratory kiss between them signals a shift from a professional partnership to a romantic one, complicating the stakes for everyone involved.
  4. The Betrayal and Disclosure (Episode 6): In "RV Shangri-la," the tension peaks when it is revealed that Pryce has been paying Zero behind Santi’s back. This moment of betrayal is heartbreaking because it plays into Zero’s deepest fears about being a "tool" of the system. The fallout leads to Santi lashing out and calling Zero a "clown," a moment that Lilli Kay plays with devastating quietness.
  5. The Bus Station (Episode 7): Zero’s conversation with Mitts (Marc Maron) at the bus station provides a rare glimpse into their vulnerability. They admit they needed the money but genuinely cared for Santi, highlighting the "zero-sum game" they often feel trapped in.

The Significance of Authentic Representation in Stick

The character of Zero represents a significant step forward for representation on Apple TV+. By casting Lilli Kay, an actor who identifies as non-binary/gender-fluid, the show avoids the pitfalls of "performative" diversity. Zero isn't a character whose sole purpose is to educate the audience or the other characters about their identity. Instead, they are a character who happens to be gender-fluid while also being a skilled strategist, a loyal friend, and a biting critic of social norms.

This authenticity extends to the writing. The show doesn't shy away from the microaggressions Zero faces in the conservative world of professional golf, but it also doesn't let those moments define the character. Zero’s strength comes from their refusal to be anything other than themselves, a trait that eventually becomes a source of inspiration for Santi, who has spent his life trying to fit into the boxes his parents and coaches built for him.

How Old is Zero Compared to Actor Lilli Kay?

A common question among fans is the age gap between the actor and the character. In the world of Stick, Zero is depicted as a young adult, likely in their early to mid-20s. This age range is crucial because it places Zero in a "bridge" position—they are old enough to have experienced the cynicism of the workforce but young enough to still relate to the 17-year-old Santi Wheeler.

Lilli Kay was born on March 18, 1996, making them 29 years old during the 2025 release of the show. While Kay is slightly older than the character they portray, their youthful energy and contemporary style make the casting seamless. The age difference actually adds a layer of "world-weariness" to Zero that fits the character's background as someone who has already been "through the ringer" of life before landing at Sparling Meadows.

Frequently Asked Questions About Zero in Stick

Is Zero based on a real person? No, Zero is a fictional character created by showrunner Jason Keller specifically for the series Stick. However, the character’s personality and social outlook are designed to reflect modern Gen Z and Millennial perspectives.

Does Zero stay as Santi's caddy for the whole season? Zero becomes the caddy in Episode 4 and remains in that role for most of the season, though their professional relationship is severely tested in Episode 6 following the revelation of Pryce’s payments.

Will Lilli Kay return for Stick Season 2? While Apple TV+ has renewed Stick for a second season as of July 2025, the full cast list for the next installment has not been officially confirmed. However, given Zero's popularity and the unresolved romantic and professional threads with Santi, it is highly anticipated that Lilli Kay will return.

What is Zero's real name in the show? Zero’s birth name is Christina Marie Duffy, though they almost exclusively go by Zero throughout the series.

Summary: The Future of Zero in the Stick Universe

As Stick moves toward its second season, the character of Zero stands as the show's most successful invention. By breaking the mold of the traditional "love interest" or "sidekick," Zero has elevated the series from a standard sports comedy to a nuanced exploration of identity, class, and mentorship in the modern age.

Lilli Kay’s performance has garnered critical acclaim, with many pointing to Zero as a prime example of how to write and perform "non-conforming" characters with depth and agency. Whether Zero continues to carry Santi’s bag or strikes out on a new path, their influence on the world of Stick is permanent. They have forced the characters—and the audience—to look past the fairways and consider the human cost of the game. For anyone following the series, Zero isn't just a member of the cast; they are the heart of the story's revolution.