Title of can indicate you what was film about. In the beginning there is a fight in the village. It is caused by rebellion of villagers, who are upset with old cruel king. King rode his horse across the village and he was killing rebels, but they stopped and threw him of his horse.

His son, prince Einon  tried to help king but he was seriously injured and he almost died. But his servants brought him to cave. There lived dragon which saved Einon by giving him a part of his heart. So it means that when one of them dies second will die too. Einon had to promise that he won’t be bad like his dead father. But he hadn’t been good character because he turned to evil.
There was also good warrior who wanted to kill all dragons in country. But dragon and warrior made a deal. Dragon will pretend his death. People will give money to warrior because of killing dragon.

But Einon hired several dragon slayers. They caught dragon in Einon’s order. Because he realized that if dragon dies he will die to. So he wanted to have dragon in safety in his castle. Warrior had to kill the dragon. Dragon went to stars and Einon died too.