The first king of Aurea leads an attack on the dragon; the attack is a failure, and the king is left at the dragon’s mercy.
Centuries later, Elodie, daughter of Lord Bayford, receives a proposal from Queen Isabelle of Aurea to marry Prince Henry. On Bayford’s advice, Elodie accepts to help their impoverished people, and she and her family sail to Aurea. Elodie and Henry walk in the gardens to “get to know each other”. The two initially both seemi disinterested in each other, but begin to bond as they both share a desire to travel. Elodie’s stepmother, Lady Bayford, seeks out the queen hoping to chat and strengthen their familial bond, but Isabelle rebuffs attempts to become acquainted, leading Lady Bayford to implore Elodie to end the engagement to no avail.
After the wedding, Elodie and Henry take part in an ancient ritual in the mountains, supposedly to celebrate their union. The queen, dressed as a priestess, describes the pact between the first king and the dragon in which he had to sacrifice his three daughters for peace. Elodie is given a gold coin to throw into the chasm, making her believe that it is the payment to the dragon. Henry insists on carrying Elodie across the narrow path over the chasm, then throws her down into the dragon’s lair.
After her initial shock subsides, Elodie finds items left by other princesses and realizes she is a sacrifice. The dragon enters the lair, asks her name and taunts her before chasing Elodie and burning her leg as she flees. Elodie bandages her leg, and determinedly, she begins to explore the surrounding area and finds an illuminated cave with glowing worms, which she collects as a light source. The dragon finds her again, and upon fleeing, Elodie finds a chamber with the note “Safe Here She Cannot Reach”. This chamber also has a wall with the names of past victims and a map carved into the wall. While Elodie sleeps, the glowing worms heal the burn on her leg.
Elodie follows the map, but it leads to a dead end at high vertical drop on the side of the mountain. She discovers the remains of dead dragon hatchlings and therefore the reason for the royal sacrifices. A rescue party led by Lord Bayford arrives. The dragon kills Bayford and his men, but the distraction allows Elodie to climb a rope to escape the mountain. She then rides one of the horses left by her father’s men and hides in a small rock while the dragon burns the area surrounding the mountain in an unsuccessful pursuit.
The conflagration alerts Isabelle that Elodie’s sacrifice has failed, causing her to have Elodie’s sister Floria kidnapped as a replacement. Elodie returns to the mountain to rescue Floria after learning of the kidnapping from her stepmother. The dragon leaves Floria alive as bait for Elodie.
Elodie creates a diversion to distract the dragon so she can reach Floria. Telling her sister to hide, she confronts the dragon and tries to convince her that they’ve both been deceived by the Aureans. At first the dragon refuses to believe Elodie, stating that the first king’s attack was unprovoked. The dragon then attacks her, but Elodie tricks her into burning herself. After her defeat, she then heals the dragon with some glowing worms.
Elodie and the dragon then interrupt another wedding at the palace, exposing the Aurean’s scheme. Elodie advises the new bride and her family to flee, and the dragon burns the palace with all the Aurean royals and nobles there. Elodie, Floria, and Lady Bayford sail home with supplies and accompanied by the dragon.