When Paxon Leah uses the Sword of Leah for the first time against the sorcerer Arcannen, who had kidnapped his sister Chrysallin Leah, he activates the magic of the sword. With the magic, 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, and Paxon is summoned to Paranor by Aphenglow Elessedil, Ard Rhys of the Druids. Sebec is the Druid sent to Paxon's home to convince him to come to Paranor. Paxon's first impression of Sebec is his friendliness and trustworthiness, and he notes the way Sebec manages to charm his mother Zeatha, who is not a person who has a kind view of Druids.
At Paranor, Paxon accepts Aphenglow's invitation to stay and train to become the Blade of the Ard Rhys, a warrior in service to the Druid Order, sworn to protect them from the evils that stalk the Four Lands. Paxon's new life quickly becomes one of training and adventure with his new Druid friends, learning about magic with Sebec, training for combat with Oost Mondara, and traveling the Four Lands with Starks so that he can protect the Druid on his missions.
However, Arcannen is still at large and he is able to kill the guards the Druids had sent to watch over Chrysallin and abduct her once more. Paxon and Starks go after him in Wayford, where the witch Mischa is torturing Chrysallin under Arcannen's orders. Paxon kills a creature of magic sent by Mischa to pursue Chrysallin, and a traumatized Chrysallin kills Mischa herself using the wishsong. Arcannen gets away, but not before killing Starks using the Stiehl, which he had stolen from the Druids.
Chrysallin is catatonic after using the wishsong, but back at Paranor, she lashes out against the Ard Rhys with the wishsong when Aphenglow tries to visit Chrysallin in her chamber. The Ard Rhys suffers only minor injuries, and everyone realizes that Chrysallin has been tortured mentally and brainwashed into thinking that Aphenglow is responsible for her torture, all as part of an attempt by Arcannen to use Chrysallin to kill the Ard Rhys.
Paxon returns to Wayford, ostensibly to find some clues that might help bring Chrysallin out of her traumatized state, but also to avenge Starks' death by killing Arcannen. As the two battle once more, Arcannen realizes he is about to be overpowered and offers to give Paxon a potion that will cure Chrysallin of the effects of her torture if Paxon will let him go. Although deeply conflicted, Paxon realizes that healing his sister is more important than gaining revenge, so he agrees to the exchange.
Back in Paranor, Paxon administers the potion to Chrysallin, who comes out of her catatonic state fully healed, not even able to remember what had been done to her. He tells Aphenglow about how hard it had been for him to have to choose between the chance of maybe saving Chrysallin with a potion and the chance to avenge Starks by killing Arcannen.
Shortly afterward, Aphenglow travels out of Paranor in her personal airship with Paxon, Sebec, and several of the Trolls who serve in the Druid Guard. When they reach the plains of the Streleheim, Aphenglow announces that Sebec is the traitor within the Druid Order who has been passing information and artifacts of magic to Arcannen. It is revealed that Sebec is not only responsible for the deaths of the Druids guarding Chrysallin which allowed her to be kidnapped a second time, but also for the theft of the Stiehl which indirectly led to Starks' death.
Sebec had also told the Ard Rhys to go see the catatonic Chrysallin even though he knew Chrysallin would try to kill her with the wishsong, and he even attempted to steal the crimson Elfstones by removing the wards Aphenglow had put in place to protect them. Aphenglow had anticipated Sebec and had put the wards in place with his help, which is how she was able to confirm that Sebec was the traitor, as only one who had known how the wards were put in place would have been able to dismantle them.
Although Sebec protests his innocence at first, he eventually confesses, admitting that he was recruited by Arcannen to use his powers of persuasion and ability to gain the trust of and get access to the Druid Order. Aphenglow has the guards execute him.
Both the Ard Rhys and Paxon are distraught over their betrayal at the hands of someone whom they'd assumed was a friend. On the way back to Paranor, Aphenglow tells Paxon that his life as protector of the Druids will be no different, that it will be filled with disappointments and deceptions that will bring sadness, and that it will be filled with hard choices like the one he made to spare Arcannen's life.
Despite the warning, Paxon insists that he wants to stay at Paranor, making Aphenglow smile.
Five years later, Sebec's betrayal and Starks' death still weighs on Paxon, and his grief is compounded further by Aphenglow's death from old age and the killing of Avelene, another of the Druids he had been introduced to when he first came to Paranor. He requests a leave of absence from the new Ard Rhys, Isaturin.