From the Flap:

A tale of archetypal heroes and sweeping adventures, of dragons and princes and evil wizards--as only Stephen King can tell it!

The passage through the castle is dim, sensed by few and walked by only one. Flagg knows the way well. In four hundred years, he has walked it many times, in many guises, but now the passage serves its true purpose. Through the spyhole it conceals, the court magician observes King Roland--old, weak, yet still a king. Roland's time is nearly over, though, and young Prince Peter, tall and handsome, the measure of a king in all ways, stands to inherit the realm.

Yet a tiny mouse is enough to bring him down, a mouse that chances upon a grain of Dragon Sand behind Peter's shelves and dies crying tears of fire and belching gray smoke. A mouse that dies as King Roland does. Flagg saw it all and smiled, for now Prince Thomas, a young boy easily swayed to Flagg's own purposes, would rule the kingdom. But Thomas has a secret that has turned his days into nightmares and his nights into prayed-for oblivion. The last bastion of hope lies at the top of the Needle, the royal prison where Peter plans a daring escape . . .

Writing with the wit and power that have enthralled millions, Stephen King has taken the classic fairy-tale form and transformed it into a masterpiece of fiction that will captivate readers of all ages.