Generate a question about the following movie plot: Author Roger Cobb is a troubled man, having been separated from his wife (Kay Lenz), their only son Jimmy disappeared without a trace, and his aunt has committed suicide by hanging. On top of everything else, he has been pressured by his publisher to write another book. To the chagrin of his fans and publisher, Cobb plans a novel based on his experiences in Vietnam instead of another horror story as a way to purge himself of the horrors that he had experienced while there. After his aunt's funeral, Cobb decides to live inside her house to write, instead of selling it as recommended by the estate attorney. After moving in, Cobb begins to have powerful graphic nightmares, including thoughts about his military ally Big Ben, who died in Vietnam. In addition, strange phenomena spring forth from the house, haunting him in his waking hours as well. He tries communicating his fears to his next door neighbor named Harold, but he thinks that Cobb is crazy. One night while investigating a noise coming from his late aunt's bedroom, Cobb is attacked by a deformed monster inside the closet. Soon, more attacks occur: levitating garden tools attack him, his wife appears and transforms into a hideous hag-like creature to attack him, and gremlin creatures attempt to kidnap a neighbor's child that Cobb is reluctantly babysitting. Eventually, Cobb discovers an entry into a sinister other-world through the bathroom medicine cabinet and is pulled into the darkness, where he fortuitously locates his lost son Jimmy. Cobb manages to escape with Jimmy, but are soon confronted by an undead Big Ben who wants revenge on him; Cobb did not help him during Vietnam and instead was taken prisoner and tortured before dying. He confronts Ben, no longer afraid of his fears anymore, and destroys him with his own explosives as he and his son escape the burning house. In the end, he triumphantly glances back at the house while regaining control of his life and reunites with his wife and child.
Who wants revenge on him?