In what ways in Nadine's story similar to a fairy tale? In what ways is it different? Would the story be more or less effective without the narrator's introduction?
Gardner makes the story like a fairy tale by making its setting and characters idyllic. The man and his wife "loved each other very much" and "had a little boy and they loved him very much." They had a cat and dog and a car and "a caravan trailer for holidays and a swimming pool" which was fenced for safety purposes. Even their housemaid was trusted and their gardener as well. Everyone loves each other and they have everything they want. They even have a "witch," but she's a "wise old witch"--the husband's mother, who cautions them against taking anyone in off the street, which seems like good advice on the surface.
The use of the phrase "happily ever after" is the stuff of fairy tales, but how Gardner uses it--from the beginning of the story and throughout--is not fairy-tale-ish at all. It is our first (and ongoing) indication that this is a satire of a fairy tale. Another way she veers from typical fairy tale fare is the couple's very modern obsession with protecting their family and belongings, even to the extent that they imprison themselves against the outside world. Despite all the remarks about how they're living "happily ever after," the tale does not end that way: their innocent little boy is sliced into a "bleeding mass" and has to be hacked free of the "DRAGON'S TEETH" concertina wire they'd placed atop their already high fence to protect themselves against the outside world.
The story would work just as well--if not better--without her introduction.