The trailer introduces Roman (Dylan O’Brien) navigating the aftermath of his identical twin’s death, haunted by grief and identity loss. At a bereavement support group, he meets Dennis (James Sweeney), another twin survivor. Their friendship blossoms into intense dependency, offering solace—but when Roman meets Dennis’ coworker Marcie (Aisling Franciosi), unsettling secrets surface.

A tonal shift mid-trailer reveals the story’s unexpected layers—a Hitchcockian edge emerges amid awkward humor, identity complexity, and emotionally raw revelations. Themes of masculinity, trauma, and connection are explored with both discomfort and empathy. The filmmaking is emotionally precise, surprising, and darkly funny. Viewed at Sundance, where Twinless won the Audience Award and O’Brien earned a Special Jury acting prize, the film impressed critics with its daring emotional honesty and sharp framing.