explain the importance of the storm. what happened to the carnival people when the storm came?

gradesaver's analysis of this section is by far the best you'll read;

"The prologue tells us that Halloween comes early this year, at three hours past midnight on October 24th. This is the time at which the train arrives, so the carnival's arrival marks the beginning of Halloween. It is here that we also realize that there is no approaching storm in the conventional sense. The storm, which Tom Fury said would be "no ordinary storm", is indeed no storm at all. The storm is the carnival, and the approaching train, whose steam looks like the beginnings of a storm cloud, marks its arrival. We don't know whether or not Jim ever removed the lightning rod from his house, but it is a safe bet that his decision - for good or ill - will play an important role in the rest of the novel.

The Mirror Maze is set up as one of the most evil parts of this storm/carnival. It clearly plays off of the novel's already established theme of dissatisfaction with one's age, and we can bet that Charles's obsession with his own age will at some point interact with the age-altering properties of the Maze. It is worth noting that mirrors and windows are symbolic of age in this novel. Three examples so far: first, according to Will, his father looks like him "in a smashed mirror"; second, Charles, upon hearing the whistled Christmas carol imagines children walking around amongst the tired and dirty faces of adults whose faces are unwashed of sin and "smashed like small windows by life that hit without warning"; and third, the narrator's musings on an infinite series of mirrors whose images increase with age.

The Mirror Maze, when it appears in Chapter 15, capitalizes on the ominous promise of these images. It seems likely that had the boys not rushed in to save Miss Foley, she would have been stuck in the Maze forever, lost in the strange effect it has on time, age and reality. The Maze is paradoxical: Miss Foley sees a vision of her younger self "drowning," yet she herself grows older. Moreover, Miss Foley doesn't just see a younger image of herself reflected in the mirror, she sees another person acting independently. This younger version of herself speaks to her and seems to think that Miss Foley is the reflection while she (the young "refection") is in the Mirror Maze.

This paradoxical move, while to some degree inexplicable, acts out the anxieties of age experienced by the older characters in the novel. Charles, for instance, feels older when he contemplates his childhood, just as Miss Foley ages when she sees her younger self. Moreover, Charles feels a younger self trapped within -- whom he feeds with his drink a day, among other things -- like an independant being. He feels as though that past, innocent self is the "real" him, and the aging body the false. In general, then, the carnival, and especially the Maze, make concrete the paradoxical anxieties of adulthood, which emphasize age even while reflecting on youth.

The book doesn't just address these anxieties in concrete images, though; it also features ruminations like those in Chapter 14, where the arrival of the train at 3:00 a.m. brings on for Charles thoughts of death, mortality, and old age. He begins to think that his son is not really his own. He does not harbor thoughts or suspicions of infidelity. Rather, he considers the process of conception and birth and thinks that his role in the whole thing was minimal at best, compared with the role of the mother. Fathers everywhere must feel this way, he thinks. Fathers provide one half of a seed, so to speak, but the child grows in the mother. What's more, it is the mother who "makes the flesh" of the child. And it is the process of heredity, children begetting children ad infinitum, that Charles defines as "Time". Looking at it this way, he thinks, women "nest in Time" - i.e. they play a continuous active role throughout - whereas men are really more like bystanders, waiting for their own time to be over, as Time itself marches on. They are "blind to the continuity."