Known facts, not guesses.

The Voyage of the Jerle Shannara by Terry Brooks. In the magical world of the Four Lands, Walker Boh undertakes a perilous quest aboard the airship Jerle Shannara to recover an ancient magic from a distant land. But dark forces pursue them, including the mysterious Ilse Witch whose power rivals that of a Druid. A thrilling addition to Terry Brooks' beloved Shannara saga.