Following a forced move from Noah's Mountain, ten-year old Lindy Cooper, upon arriving in Lock Seven, West Virginia, again utilizes imagination to craft Woodland Palace, an incredible marble castle she fashions as sanctuary for her imaginary playmate and protector, Princess Twilight. She conceals the palace within a secret grove of ancient willows that, unbeknown to her is also home to a kingdom of illusive woodland fairies, and a six-inch, armor-clad prankster, Sir Notnert. While struggling to find her place in this strange flat land, Lindy finally finds a human friend. However, a task must be completed before she can devote her time to strengthening this friendship: she and Princess Twilight must decipher baffling verses of rhyme stitched into the ancient tapestry hanging in the palace ballroom, if they are to find three lost scrolls containing incantations they believe will transform Prince William from unicorn to human, and then transport him and Guardian from Amethyst Cavern. Time is growing short for as the result of Lindy' prolonged absence from Noah's Mountain; Princess Twilight's home is slowly disintegrating, and unless the mystery of the tapestry is deciphered soon the crystal cavern, once created to shelter her loved ones, may soon become their death tomb.