Grief has long been an interesting theme that the movie industry has explored over the past decades. Whether it’s drama, comedy, action, or even horror, there really is no shortage of films about such a complex emotion and experience. But the specific story of a twin grappling with the death of their other half (someone they’ve always shared life with) remains rarely explored, if at all. That’s the concept bravely explored in Twinless, which first premiered at the 2025 Sundance Film Festival. Following the leak of some scenes from the movie just a few months ago, the Dylan O’Brien-starring comedy drama has finally unveiled its official trailer. Set to hit theaters on September 5, the thought-provoking flick is written and directed by James Sweeney (Straight Up), who also stars in the film as one of the twinless twins — or so it seems.

The trailer for Twinless opens with O’Brien’s character, Roman, who is still reeling from the death of his twin brother. He reluctantly joins a support group for twins, presumably at the urging of his mother, who believes he needs help. There, Roman meets Dennis (Sweeney), who — despite their differences — he immediately forms an unlikely connection with, drawn together over their shared experiences of losing their other halves, and the feeling of struggling to adjust to doing things alone. Like what Roman tells Dennis in the trailer, “You get me.” From then on, they started doing things together, including grocery shopping, late-night gaming, catching live sports, and even hitting the gym.

They’re practically inseparable by that point. However, what they don’t realize is that they know very little about each other. According to the official synopsis, both Roman and Dennis “search for solace and an identity without their other halves and soon become inseparable outside the group. But when Roman meets Dennis’ ebullient co-worker, Marcie, all is revealed to be not what it seems, as each man harbors secrets that could unravel everything.“

Who Else Stars in ‘Twinless’?

O’Brien, who first gained mainstream attention with his stint in Teen Wolf, has been taking on more intricate roles lately. That includes his starring roles in Love and Monsters, The Outfit, Not Okay, Ponyboi, and Caddo Lake. In Twinless, O’Brien plays the dual role of twin brothers, Roman and Rocky. The film also stars Lauren Graham (Gilmore Girls) as Lisa, Aisling Franciosi (The Nightingale) as Marcie, Chris Perfetti (Abbott Elementary) as George, Tasha Smith (For Better or Worse) as Charlotte, François Arnaud (Midnight, Texas) as Sammy, and more.

Twinless hits theaters on September 5. You can watch the trailer above.

Twinless

Release Date

September 5, 2025

Runtime

100 Minutes

Director

James Sweeney

Writers

James Sweeney

Producers

David Permut, Ali Jazayeri, Elizabeth Destro, Miky Lee, Dylan O’Brien