In a seemingly peaceful valley live three children and their father. The family lives in secret in a cave on a hill overlooking a small village below. The children, Corin, Maia and Adras are forbidden to set foot down to the village, though Corin asks about it every year hoping their father, Marsus, will change his mind.
The children soon celebrate their fifteenth birthday and receive their present; a locket with a picture of the family inside. The following night, Corin and the other children share the same startling dream ordering them to return to the place of their birth so their true journey can begin.
Confused and frightened the children seek out their father for answers...
Marsus drops a bit of a bomb on the three siblings. He tells them of a legend about three children descending from the stars with the power of the heavens themselves. Corin, Adras and Maia are those children and they can feel themselves being called back to the true place of their birth, the mountains surrounding the valley. They deceide to head out first thing the morning.
Marsus with his children in tow set out across the valley to the nearby mountain range. After deceiding to make camp for the night, Corin follows a rather irate Adras off into the woods to find out what exactly his problem is. Adras confesses rather harshly that his faith in his brother's abilities is somewhat lacking. As the two brothers begin to argue, their shouting arouses the ire of a nearby pack of Timber-Horns, wolves with the horns, tail and disposition of raging bulls.
Corin and Adras take off back towards the safety of Marsus and Maia, but run right past their camp. After defeating some of the pack of Timber-Horns and leaving Maia in safety, Marsus runs off after Corin and Adras. Marsus catches up with Corin only to be ambushed from behind by one of the wolves. After a short sturggle that leaves Marsus with a nasty and bleeding wound in his shoulder, the brothers and their father are reunited and head back to camp.
That night, Corin feels guilty about his father getting hurt because of him and Adras consoles him and says sorry for yelling at him. Even though Marsus' wound seems severe, he brushes it off and group continues towards the mountain range the next morning...
After a long journey scaling the mountain range, the group find the cavern Marsus remembered all those years ago. Strange glowing symbols appear on the walls as the children enter. The children are happy to have finally found the place of their birth but their joy is short lived as Marsus finally succumbs to his wound and collaspes. The entire cavern shakes and a bright light engulfs the room transporting just the children to a darkened shrine. The same mysterious symbols line cover the walls along with vivid murals.
Maia inspects one of the many murals and is momentarily possessed by an unknown pressence. It tells them of the battle between Illune, the young goddess of their world and an evil being known simply as Chaos. The battle ended in a stalemate with both sides being placed in sealed prisons. The children learn that the reason they were created is to find Illune's seal and release her. They are the 'Star Crossed' children, beings with the power of the heavens but the hearts of mortals. Only their power can break Illune's seal.
Three hooded beings, dressed exactly as the one from the children's shared dream appear above them and are revealed to be the ones that took over Maia's mind. They tell the children that they must be tested to make sure they still have the balance between heaven and earth within them and they really don't have a choice in the matter. If they fail the trials, they die. Corin stubbornly refuses the trials but when shown that the hooded beings hold a weakened Marsus captive in a glowing ball, the children quickly give in and are transported to their respective tests.
Adras finds himself alone on a darkened, empty plane, but not for long as his injured and now gravely ill father is transported along with him. After changing his motivation from passing the trial to getting his father out of there, Adras is confronted by the Guardian of the realm he's standing in. The Guardian tells Adras he has not yet reached where his trial is suppose to be. The gateway to his trial must be opened with the sacrifice of a life, i.e. Marsus. Adras refuses to just hand Marsus over and tries to fight the Guardian. However, the Guardian easily trounces Adras repeatedly until Marsus can't bear to watch Adras get the stuffing beat out of him any longer. He tells Adras to leave him and continue on. Adras again refuses and is sucked into a brilliant light.
Susano, one of the Three Stars connected to the Star Crossed children appears before him to determine why Adras would not give up even though he had no chance of winning that fight. Adras tells Susano that his family is counting on him to win. Pleased with his answer, Susano grants Adras her power of flame, on the condition that he puts his money where his mouth is.
Adras returns to the plane in a flash of light and uses his new powers to defeat the Guardian. After the fight, Adras finds that his father has vanished again and he is left to wander away alone.
Meanwhile back at the temple, the three hooded beings discuss the progress of the children. Susano, who reveals herself to be one of the hooded beings, is very happy. Yuta disagrees and questions why they go through some much hardship for just one human. Marsus, who'd been watching from Yuta's glowing ball tells him that love is the reason before passing out. Yuta still disagrees.
Corin's trial begins already in progress as he's chased by another Guardian on a plane similiar to Adras'. Corin evades numerous attacks until the Guardian causes a massive earthquake with his boulder sized arm and splits the ground from under Corin. Adras appears and saves Corin from VERY nasty fall. He then proceeds to show off his powers a bit upside the Guardian's face. Corin is jealous and questions whether he'll be able to be as good as Adras.
Soon Adras is flung away and slammed into a nearby rock slab. Corin stands up to the Guardian finally in an attempt to prove he can stand on his own. Unfortunately, the Guardian flings him away as well and closes in for the kill. Adras valiently steps in the way of the Guardian's giant rock arm and is slammed in the stomach. With his last bit of strength, Adras pulls off the Guardian's rock arm and tosses it aside. Corn catches Adras as he falls, receives a bit of last minute wisdom from Adras before he passes out and Corin is transported in front of Takane, the second star.
Takane asks why Corin is here and if he's truly strong enough to protect his family. Corin defends himself and proves to Takane that he has what it takes. Takane agrees, transports Corin back complete with a brand new sword and wind powers. Corin finishes off the Guardian but when he doubles back for Adras they are both sucked into a black void.
Back at the temple, Takane is very pleased with Corin while Yuta remains unimpressed. Time is running out for Marsus and he believes the children may not save him soon enough.
Maia's trial starts quickly as a rather cocky Guardian attacks her. Defenseless, Maia is soon entangled in the Guardian's vine arms and suspended high in the air. Before the Guardian can skewer Maia on his sharpened vines, Corin swoops in from the side and slices him to ribbons with his sword. Corin chooses not to tell Maia about Adras because it would only distract them from the task at hand. However, the worst appears to be over after Maia's weapon, a bow, materializes in her hands after the Guardian's supposed "death".
Suddenly a smaller version of the Guardian bursts from the ground and attaches itself to Corin's back. It takes control of Corin's body and forces him to attack Maia. She barely dodges, convinced that simply fighting Corin isn't the way to save him. Maia's bow moves on its own and takes aim at Corin. Maia fights for control against it and is hit by Corin's attacks. She is tossed through the air and slammed to the ground.
As Corin pleas with the fallen Maia to get up, Yuta, the third star, appears before her. He asks her why she didn't fight back. She explains that there's always options, more than one way to figure things out. She believes these powers aren't just for fighting. Yuta reluctantly gives her a chance to prove that she has the power to think before she acts.
Yuta returns her to face Corin. Ice shards appear around Maia and she devises a plan. She severs the hold the Guardian has on Corin's arms and torso and shoots the body with an ice arrow from her bow. Pleased with herself, Maia collaspes as a freed Corin runs to her. Suddenly, they are both transported to a star filled field where the hooded figures greet them. The bodies of Adras and Marsus appear beside Corin and Maia.
The Three Stars, Takane, Susano and Yuta reveal themselves and revive Adras, Maia and Marsus. The family is finally reunited and the Three Stars apologize for the harshness of the Trials. The three children are given magical, runed bracelets that connect their hearts directly to the hearts of their respective Stars. The Three Stars transform back into their animal forms and take the three children and Marsus through a portal back to their world.
Before leaving them, Marsus asks the Stars why was he chosen to watch over the children. The Three Stares admit that it was not they who chose him.
Corin, Maia and Adras finally return to their cavern home with their father in tow. However, things are not as they left it.