After years of travel in the wide world, Derry Melyvante has made his home near the quiet woodland village of Haverdell. Derry lives with his dog Barrow on a small island outside town and spends his days in singular pursuit of his craft and passion: Derry is a gardener, a master of woodlore and plants and green growing things, a man whose heart belongs in the trees and high hills and soft grassy meadows around sleepy Haverdell. He and Barrow have built a home and found friendship in Haverdell—a quiet, fulfilling life.

An unknown blight has taken hold in the Brightoak Tree. Derry's efforts to care for the great tree are interrupted by the appearance of a knight from the king's court with a summons for the gardener of Haverdell—a message specifically requesting Derry by name. The gardener is escorted to the capital by Caedan, Knight of Mira, where he is asked to investigate a similarly strange affliction in the holy gardens of the king. Derry performs his work, makes his recommendations for care, and thinks to return to Haverdell and the gentle calm of his chosen home.

But strange magic and stranger maladies are afoot, both in the king's court and in Haverdell. Derry and Barrow swiftly find themselves embroiled in affairs beyond their imagining, as monsters and blights and shadowy figures foment catastrophe throughout the land. Plants have begun to turn against the gardener. The king has been kidnapped. Allies have become traitors. Together, Derry, Barrow, and Caedan seek to end the mayhem and find a solution to the strange curse that has gripped the kingdom—before wild plant-monsters overrun everything and swallow the land into their greedy, leafy maw. Even if the trio is successful, they will have to contend with traitors in the king's court, magical devices now stolen by rebels, and ancient temples reawakened for unknown purposes...