In a mythical time when dragons were thought to be extinct, the last remaining dragon forms an unlikely bond with a disillusioned dragon-slaying knight. The knight, Bowen, believes in a code of honor that he thinks has been forsaken by the people, including his former pupil, the tyrannical King Einon, whose oppressive rule is causing untold suffering to his subjects. Bowen blames the dragon race for Einon's corruption, as legend holds that a dragon's heart has the power to heal and corrupt in equal measure. However, upon meeting the dragon, whose intellect and wisdom are as formidable as his fearsome appearance, Bowen's animosity turns to camaraderie, as he realizes the dragon might be his ally rather than his enemy.

Together, Bowen and the dragon, whom he names Draco, form a partnership to perform staged dragon-slaying exhibitions, which provide entertainment to the locals while allowing them to make a living. Throughout their travels, they meet a spirited young woman named Kara, who seeks vengeance against King Einon for the devastation brought upon her family and her village. Kara joins them, thinking Bowen's cause aligns with her own. As the trio unearths deeper secrets about King Einon's ascent to the throne, they must navigate a complex web of betrayal, honor, and the bonds of friendship, leading them to confront the king and his reign of tyranny. Their journey poses a profound question: Can the heart of a dragon save the kingdom from ruin, or will it doom them all?