Domhnall Gleeson shines in delightful Sundance film The Incomer

A brother and sister have spent their entire lives on a secluded island, crafting their own set of rules, society, and beliefs. Much of this stems from their father’s last wish: to protect the island at all costs. So, when a timid man played by Domhnall Gleeson arrives years later, things take a turn for the worse for him. However, his arrival might just be the best thing that could happen for everyone involved.

This is the simple premise of The Incomer, a new film that made its world premiere this week at the 2026 Sundance Film Festival. Written and directed by Louis Paxton, it’s a fascinating mix of mythology, comedy, and coming-of-age themes, with a sprinkle of animation thrown in for good measure.

Paxton first introduces us to Isla (Gayle Rankin) and Sandy (Grant O’Rourke), the isolated siblings who fill their days dressing up as birds, sharing stories, and doing everything they can to block out the world beyond their beloved island. You might expect such characters to be a bit odd, and Isla and Sandy certainly fit that bill. Yet, they also exude a wholesome charm and a relatable sense of capability.

Gleeson, known for his roles in Star Wars, Harry Potter, and Ex Machina, plays Daniel. He works for a small government agency tasked with relocating people from places they shouldn’t be. So, he’s sent to Isla and Sandy’s island to carry out this mission. But Daniel isn’t exactly the assertive type, and Isla and Sandy aren’t exactly welcoming. They view him as nothing more than an “incomer” and make it clear that he’s not welcome.

The fish-out-of-water scenario, which works both ways, is played for both laughs and heartfelt moments. It’s just as funny when Daniel attempts to explain the internet to Isla and Sandy as it is when they share their quirky daily routines with him. Picture this: he’s trying to clarify what being a vegan means while they’re happily munching on a seagull they just caught. Yet, amidst all the hilarity, there’s a genuine curiosity and wonder blossoming among the three of them. Isla and Sandy have only ever known each other, and Daniel has never encountered anyone quite like them. A bond starts to form, leading to trust, and we get to witness their friendship evolve into something truly special.

This whole dynamic is beautifully layered with a mythological twist. Isla and Sandy are captivated by the stories their father told them about the fearsome sea creatures that dominate the island and the mystical powers of the birds soaring above. Meanwhile, Daniel, a Dungeons & Dragons enthusiast, dazzles the siblings with his extensive knowledge of fantasy lore. It’s all so charming and delightful—until Daniel’s bosses come knocking.

There are moments in The Incomer where you might think you know exactly where the story is headed. Times when it feels a bit predictable. During those instances, it almost seems to lose its direction. But as the narrative unfolds and builds toward its climax, everything comes together in such a satisfying way that I found myself grinning from ear to ear. Ultimately, that’s the magic of The Incomer. It’s a film that highlights what truly matters in life—the bravery to take risks and the profound impact of how we treat one another.

Gleeson brings his signature charm and awkwardness to the film, and it’s fascinating to see how that persona gradually unravels throughout the story. This transformation is even more compelling thanks to the outstanding performances by Rankin and O’Rourke. Each actor offers a unique and captivating perspective on how isolation can affect a person, and you won’t find characters quite like them anywhere else. They’re innocent and naive about the world, yet they possess a stubborn confidence that makes you root for them, even when they’re clearly mistaken.

As for The Incomer, it hasn’t landed a U.S. distribution deal just yet, but I’m sure that’s coming soon. It’s a quirky, heartfelt film that’s sure to please audiences. You can catch it this weekend through the Sundance Film Festival’s online portal.