There are two worlds, or realms if you will. There is the Realm of Reality, or the Human World, and there is the Realm of Imagination, populated by figments of our imagination. Bizarre animals, Imaginary Friends, Heroes and most unfortunately, the vile and loathsome Monsters we conjure up in our minds when we're most frightened.
Thomas Llewellyn doesn't know anything about this other world; neither does his brat of a little brother, Isaac nor their young cousin, Emily. They soon come to learn about the existence of this strange world when they are suddenly and violently pulled from their own by a turbulent vortex. Faced with having to prove just what they are, they must try to find a way home while all the while, someone plots to keep the human children where they are so that they can be used for a terrible purpose.