After the events of the
third film, but before the
second, Fievel, his sister Tanya, and his friend Tony get jobs at the local newspaper. The Mousekewitz children and Tony meet Nellie Brie, who wants to be an important reporter, but only gets small assignments, as if she were a secretary to Reed Daley, the newspaper's editor. Nellie gets a chance when she is assigned to report on mice who disappear overnight into holes that open up on their floor all over
New York City. Reed makes up a, as Nellie calls it, "so-called monster" that lives under
Manhattan and takes mice away during the night to add more excitement to the otherwise unimportant story, intending to sell more papers. The night monster creates fears among the readers, as could be expected. Fievel begins having nightmares that cause him to lose sleep because of his fear of the monster; the film opens up with Fievel having a dream about being chased by what he thinks the monster looks like (a fiery demonic cat with a mouse trap on its tongue). When, through Tanya, he is assigned the job of following Nellie and drawing up interpretations of what the monster looks like based on witness testimony, this makes his insomnia all the worse. A particularly suspicious miniature French poodle named Madame Mousey, who has started living among the mice about this time, appears at every crime scene, claiming to be a fortune teller. The heroes finally decide to investigate her by means of the "dog council" that meets at
Central Park. They also search down one of the holes, which leads directly to a group of cats known as the infamous Outlaw Cats hiding in the sewers. All the mice that had disappeared are being held in wood cages there, to be sold off to other cats and eaten. The night monster itself, a mechanic device with ghastly flashing pictures and a circular saw, is revealed in full when it attacks the mice newspaper office and printing press to prevent them from printing the truth, which they had just discovered. A great chase scene takes place throughout both the mouse and the human newspaper offices. Reed finally wins Nellie‘s heart and ended up in a relationship. When all the cats seem to be under control, the "dog council" appears just as they are regaining consciousness and chase them all away, taking Madame Mousey with them. As the film ends, the last scene takes place at the beach, where Tony informed the Mousekewitz family that the "dog council" had chosen for the French poodle (who was the mastermind behind the night monster all along) a punishment worse than prison: returning her to her owner, Mrs. Abernathy. Mama Mousekewitz surmises saying that now that the mystery has been cleared up, Fievel finally goes to sleep, only to turn around and find him with Yasha his sister already asleep on the beach towel, to which Papa smiles and says, "You were saying?" The Mousekewitz family, including Tony and Tiger, share a group hug as Mama says, "Sweet dreams, my little Fievel. Sweet dreams". == Voice cast ==