“The Incomer,” a psychological drama set in northeastern Scotland, explores the tense dynamics between a land coordinator and two isolated siblings. Written and directed by Louis Paxton, the film stars Domhnall Gleeson as Daniel, whose task is to persuade Isla and Sandy, middle-aged siblings played by Gayle Rankin and Grant O’Rourke, to leave the remote island where they have lived since their parents' deaths decades earlier.

The story unfolds with Daniel initially approaching the siblings with a casual confidence, believing he can simply instruct them to pack their belongings and leave. However, Isla and Sandy challenge his authority, responding with hostility that includes throwing a rock at his head and defending themselves with crude weapons such as a stone-headed ax and wooden club. The siblings’ apparent disconnect from mainstream society is underscored by their unfamiliarity with common cultural touchstones, a gap Daniel attempts to bridge by recounting the plot of “The Lord of the Rings.”

Narration by Isla provides insight into the siblings’ world, suggesting that while their lifestyle might appear unusual, they consider themselves “very normal.” The film incorporates whimsical elements, including black-and-white animations depicting the mythical relationship between the siblings and local seagulls, adding a layer of folklore to the psychological tension.

As Daniel’s efforts to manage the situation drag on, his absence raises concerns within the Northeastern Scottish Council, prompting the introduction of a more assertive land council agent, portrayed by Emun Elliott. Meanwhile, Daniel’s allegiance begins to shift, complicating his role and escalating the narrative suspense.

The film’s portrayal of the stark Scottish landscape serves as a compelling backdrop, enhancing the story’s atmospheric intensity. While some aspects of the plot may feel strained, the performances by Gleeson, Rankin, and O’Rourke are consistently engaging.

The narrative builds steadily to a climax described as electrifying but ambiguous, resisting the conventions of a neatly resolved or overly optimistic conclusion. “The Incomer” is rated R for violence, language, and brief graphic nudity, with a runtime of 102 minutes. It is currently playing in theaters.