"Gregory Horror Show: The Last Train" is a short anime series that serves as a spin-off of the original "Gregory Horror Show." The narrative unfolds within the eerie confines of Gregory House, a mysterious hotel inhabited by bizarre and unsettling characters. The protagonist, a young man referred to as the Guest, finds himself trapped in this strange environment after boarding a train that leads him to the hotel. His goal is to escape, but he must navigate the hotel's labyrinthine corridors and interact with its peculiar residents to find a way out.

The Guest encounters a variety of eccentric characters, each with their own quirks and motivations. These include Gregory, the enigmatic and sinister hotel owner who oversees the bizarre happenings; Catherine, a seductive yet dangerous woman who manipulates those around her; and James, a nervous and paranoid individual who adds to the tension. Other notable characters include the mischievous twins, the stoic and silent Nurse, and the ghostly Child, all of whom contribute to the unsettling atmosphere of the hotel.

As the Guest explores the hotel, he is drawn into a series of surreal and often disturbing events. The narrative is episodic, with each segment focusing on the Guest's interactions with different characters and the challenges they present. These interactions often involve psychological manipulation, moral dilemmas, and tests of the Guest's resolve. The overarching plot revolves around the Guest's attempts to collect "souls" or "keys" from the residents, which are necessary for his escape. However, each encounter reveals more about the dark nature of Gregory House and its inhabitants, blurring the line between reality and nightmare.

The series is characterized by its minimalist animation style, which enhances the surreal and claustrophobic tone of the story. The pacing is deliberate, with a focus on building tension and exploring the psychological aspects of the characters. The narrative does not provide clear resolutions, leaving much to interpretation and emphasizing the ambiguous and unsettling nature of the setting.

"Gregory Horror Show: The Last Train" is a concise and atmospheric series that delves into themes of fear, manipulation, and the struggle for freedom. Its unique storytelling and distinctive characters make it a memorable entry in the horror genre, offering a brief but impactful experience for viewers.