The story begins with young Ashin finding the resurrection plant in Pyesa-gun to cure her mother, while Joseon nobles slaughter fifteen Pajeowi Jurchens trespassing for ginseng. To prevent war, Commander Min Chi-rok frames a tiger for the deaths and uses Ashin's father, Tahab, to spread the rumor. The Pajeowi discover the ruse and wipe out Ashin's village. Ashin takes shelter at the Joseon fort, enduring years of abuse while practicing archery.
Years later, adult Ashin infiltrates the Pajeowi camp and finds her father alive, limbless, and tortured; she mercifully euthanizes him. Returning to the Joseon fort, she uncovers records proving Min Chi-rok orchestrated the massacre of her clan. Ashin revives a dead soldier with the plant, unleashes the zombie inside the barracks, and picks off fleeing soldiers from the roof with arrows. After burning the fort, she feeds the dead to her chained, infected family and heads south to deliver the plant to Physician Lee Seung-hui, intentionally triggering the downfall of Joseon.