A Useful Ghost

Nat remains anchored to the physical world because March remembers her. The story establishes that ghosts stay connected to reality through the memories of those who knew them living. Since March still holds vivid memories of his wife and their unborn child, Nat can manifest and interact with the living world. This memory bond is what allows her to possess objects, visit March in the hospital, and eventually become visible to everyone after saving Suman.

Earlier, the story explains that Tok's spirit is also anchored to the physical world because someone close to him still remembers his life.

Tok haunts the factory because his boyfriend Pin still remembers him. The narrative establishes that spirits remain tethered to the physical world when loved ones maintain memories of them. Pin's continued remembrance of Tok allows Tok to possess machinery, disrupt operations, and angrily complain about the factory's negligence in his death from congenital heart disease. This memory connection is what keeps Tok anchored and allows him to interrupt work.

The repairman Krong explains early on that many ghosts haunt the factory because someone close to them remembers their lives.

March is taken to the hospital because his family and religious authorities are disturbed by his relationship with a haunted vacuum cleaner. When Nat possesses a vacuum and seduces March in the inventory warehouse, his family views this as deeply inappropriate and concerning. The religious authorities interpret the ghost possession as a violation of spiritual boundaries, leading them to intervene and have March institutionalized for evaluation.

The family is already grieving Nat's death and the loss of their unborn child, making March's behavior appear irrational and emotionally unstable.

Electroshock therapy threatens Nat because it erases the memories that anchor her to the physical world. Since Nat exists in the living world through March's memories of her, damaging March's memory will sever her connection to reality. Suman commits March to a psychiatric institution specifically to have him undergo electroshock therapy designed to damage his memory. If March forgets Nat, her bond to the physical world will be destroyed and she will disappear completely.

The story establishes early on that ghosts are anchored through the memories of the living, making memory erasure a direct threat to any spirit's existence.

Suman wants to eliminate Nat because the ghost's presence and March's relationship with her threaten the family's reputation and business interests. Suman is under pressure from conservative in-laws who never accepted Nat. Additionally, Nat's involvement with March and her visible manifestations create scandals that complicate Suman's already difficult position, her factory is closed due to Tok's haunting, and she faces financial ruin. Suman sees Nat as an obstacle that must be removed to restore order and protect her family's legacy.

Suman is already stressed about the factory closure and losing her operating license due to Tok's spiritual violations.

Nat makes a bargain with Suman: the factory will reopen, but as a ruse to gather employees so Nat can enter their dreams and identify whose memories are keeping Tok anchored to the physical world. Financially cornered due to the haunting and factory closure, Suman agrees to this arrangement. Nat uses the opportunity to systematically investigate the employees' dreams, eventually discovering that Tok visits his boyfriend Pin's dreams, which allows her to locate the source of Tok's haunting.

Nat enters Suman's dreams earlier to plead for help and understand her resentments, establishing Nat's ability to traverse dreams.

Nat agrees to help Dr. Paul because he offers to clear the bureaucratic red tape preventing her and March from using her frozen eggs to start a family. Although Nat initially refuses the unethical request to systematically investigate dreams and treat those who remember ghosts, she capitulates when offered this personal incentive. The promise of having a biological child with March proves irresistible, despite the moral cost of erasing politically inconvenient ghosts.

Earlier, Nat and March discussed restarting their family using Nat's frozen eggs, establishing this as a deep desire for both of them.

March's relationship with Nat deteriorates because he becomes disgusted by her mass-exorcism project. While Nat successfully purges politically inconvenient ghosts, March sees this as a betrayal of their kind and a destruction of historical memory. He accuses Nat of changing so much that he's forgetting who she used to be. Rather than accept this moral compromise, March attempts to preserve the memory of the erased ghosts by studying the history of political violence, creating an unbridgeable ideological divide between them.

The story establishes that March is already studying political violence, showing his commitment to preserving historical memory.

Nat betrays March because she chooses the opportunity to finally have a child over her relationship with him. When Dr. Paul offers to clear the bureaucratic obstacles preventing her from using her frozen eggs, Nat agrees to betray March to the political establishment. This betrayal represents the culmination of her transformation, having already compromised her moral principles through mass-exorcism, she now sacrifices her husband for personal gain. The betrayal leads directly to the tragic events that end their relationship.

Earlier tension between Nat and March about her changing values foreshadows this ultimate betrayal.

March is killed or permanently forgets Nat due to a coughing fit that knocks over a bust of Nat commissioned by Dr. Paul. The bust falls on March, sending him to the hospital with serious injuries. The trauma causes him to either die or lose all memory of Nat. With March's memory of Nat erased, Nat's bond to the physical world is severed, and she fades away completely, leaving Suman alone with the baby.

The earlier electroshock therapy already threatened March's memory, and Nat's betrayal creates the emotional context for this violent accident.

Krong is not a human repairman but a ghost who was murdered. He reveals to the Academic Ladyboy that he was killed by having his feet encased in concrete and thrown into a lake. His spirit remains anchored to the physical world through his daughter's memories, but these memories were nearly destroyed by Dr. Paul's electroshock therapy as part of Nat's mass-exorcism project. The Ladyboy eventually retrieves Krong's concrete-encased feet from the lake, allowing Krong to become fully manifested and lead an attack that kills Dr. Paul and his associates.

Early in the story, Krong explains that many ghosts haunt the factory that produced the vacuum, establishing the presence of multiple spirits.

In the final confrontation, Krong and other vengeful ghosts, strengthened by the Ladyboy retrieving Krong's feet from the lake, invade Dr. Paul's home with help from his staff. They kill Dr. Paul, his family, and his associates in violent retribution. This violent ending completes the cycle of vengeance that the film has built toward, with the ghosts finally achieving justice for their murders while the human characters face the consequences of their exploitation of spirits.

The film establishes throughout that ghosts seek vengeance against those who wronged them, building toward this violent reckoning.

Nat transforms into a visible good ghost after saving Suman's life from Tok's violent refrigerator attack. When Tok, possessing a refrigerator, launches a violent assault on Suman, Nat intervenes to protect her. This act of heroism earns Nat a reputation as a good ghost, allowing her to appear in her human form to everyone around her. Previously, only March could see her true form, but after this intervention, she becomes visible to all, marking her elevation from vengeful spirit to protective entity.

Dr. Paul earlier argued that Nat is a good ghost who should be supported, establishing the potential for this transformation.