Summary/Plot

When Kendra and her younger brother, Seth, are sent to stay for two weeks with their mysterious Grandma and Grandpa Sorenson, Kendra is nervous that her grandparents won't.  But when her and Seth arrive, they discover that their grandmother is missing and that something about their Grandpa Sorenson's house and garden isn't quite right.  First Kendra notices the oddly behaving and exotic butterflies, hummingbirds, and winged insects that dance around the swimming pool in the yard and seem to examine their own reflections.  Seth, too spirited and curious to stay out of the woods they have been forbidden to enter, runs into a witch and begins to unravel the mystery of Fablehaven and finally their grandfather tells them that he actually runs a preserve full of magical creatures as endangered as they are dangerous.  Culminating in a Midsummer Night's Eve disaster, Kendra and Seth must rescue both of their grandparents and use their logic and innocence to restore the balance of Fablehaven before the evil with Muriel and the secret Society of the Evening Star can let loose a horrible demon that might destroy Fablehaven and everyone on the preserve that the two children care about.