The High Druid's Blade is the first novel in The Defenders of Shannara trilogy. It chronicles Paxon Leah's attempt to save his sister Chrysallin from the sorcerer Arcannen, Paxon's discovery that he is the wielder of the Sword of Leah and the magic of the Ohmsford bloodline, and Paxon's journey to become the High Druid's Blade.
Although legend had it that Paxon was descended from the royals and warriors who once ruled the Highlands of Leah, Paxon isn't a prince or a warrior. He oversees his family's small business that ships goods via airship freighters, and he is barely able to hold his family together. Immersed in the struggles of daily life, Paxon doesn't even have the time to realize how much he longs to leave his home in Leah and take control of his future.
When Paxon's younger sister Chrys is abducted by a stranger, he discovers that her kidnapper is the Southland sorceror named Arcannen. When Arcannen flees Leah for Wayford, Paxon races to Chrys's rescue with the only weapon he can find, an antique sword that had always hung above the fireplace. He tracks the sorcerer to his compound and battles him to get Chrys back.
During the duel against Arcannen, Paxon is stunned to discover that his sword is in fact the Sword of Leah, the weapon imbued with magic by the Druid Allanon centuries ago. Paxon is able to overpower the sorcerer and take Chrys back, but Arcannen manages to escape.
The use of magic in the battle between Paxon and sorcerer catches the attention of the Druid Order. The Druids, realizing that Paxon is a descendant of the Ohmsfords as well as the Leahs, urge Paxon return with them to Paranor and train to become the High Druid's Blade. The High Druid's Blade is a warrior in service to the Ard Rhys and the Druid Order, one who has sworn to protect them from the evils that stalk the Four Lands. The Ard Rhys in the time of Paxon Leah is Aphenglow Elessedil, who has survived the last 150 years by use of the Druid Sleep.
Paxon is taken aback by the offer but realizes that it could be the path to a different future, one of his own making. He decides to go to Paranor to train and serve the Druids for three years. His new life quickly becomes one of danger and adventure as he travels the Four Lands with the Druids, protecting them on their missions.
However, Arcannen is still at large, and there is treachery brewing within the Druid Order, meaning that Paxon's trials are just beginning.