This series follows the legend of Wilhelm Gorkeit of Tellikon (William Tell), who, as the stories say, shot an apple off of his son's head and lead the rebellion to free Switzerland.
The peaceful Kingdom of Kale is thrown into chaos after the Citadel is overthrown by the dark forces of Kreel and Xax. After his family farm is destroyed by the Xaxian army, young William Tell is visited by the mystical Kalem who reveals that he has been chosen to seek the legendary Crystal Arrow, which is the key to saving the Princess Vara and her Kingdom.
After their escape from the mines, William and his newfound friends from the rebel forces - Leon, Aruna and Drogo continue their journey to obtain the mythical Crystal Arrow. But Princess Vara seems to think she is better suited on the throne beside Xax who seems to be remaining hot on their trail. It soon becomes clear that there is a traitor amidst the group. But who is it?
William and the rebels suspect Xax is plotting with Kreel who has a reputation of delivering powerful, dark magic. After Princess Vara escapes during a battle with Xaxian warriors, William is conflicted when he discovers that there is a bounty on his head and villagers are threatened with execution unless he gives himself up.
William's bold plan to infiltrate the Citadel goes wrong when Leon is arrested after being caught talking to Alexim in the marketplace. Rather than executing Leon immediately, Kreel holds him prisoner as bait. But will William and the rebel forces fall to Kreel and Xax's nefarious plans?
The group seeks refuge in the Hidden Valley, but they soon discover that the water supply has been contaminated with a powerful hypnotic substance, which has turned the once peaceful village into an army of willing slaves. William is positive Xax and Kreel are behind it all, but there is something more to it than simply William's capture.
A statue of Xax with crystal eyes has been placed in every village as a form of surveillance for Kreel and Xax to spy over the kingdom. Lalia refuses to worship the idol and is taken prisoner. Will discovers the type of crystal that is being used to transmit the images and seeks to destroy the mine that it is sourced from. But there is also a mystery to be resolved with Lalia.
During an attempt to infiltrate Kreel in his stronghold, Kalem transforms into a bird but is sensed by Shaytana's Eye and badly wounded. In order to heal herself she must drink from the Crystal Stream but she is far too weak to make the journey alone. So Will and Aruna must assist her, leaving Leon and Drogo to protect Vara from the dark forces of Xax and Kreel.
Princess Vara has fallen ill and the group is taken in by Harana, a healer and leader of a group called The Watchers. She leads them to a bountiful valley, which does not seem to appear on any map. But it soon becomes evident that this idyllic valley is secretly controlled by Kreel. And William and the rebel forces must delve deep into their reserves and strategies to survive.
During a hunt with a group of Warriors, Xax is ecstatic to cross paths with Will and his rebel forces. After they are chased by the horsemen on an open plain with seemingly no escape, the mist clears and reveals a mysterious castle. But the group soon discovers that this is no ordinary castle. It is the Castle of Doubt, where every good thing has an evil counterpart and nothing is what it seems.
Xax and Kreel aren't the only obstacles in the hero's path for the Crystal Arrow. The evil sorcerer, Zadrim, has been working together with the scientist, Voss, to develop a horrifying strain of a deadly virus known as the Yttrium Element. William arranges for Aruna to travel to the house of Athelstan, to pose as an assistant to discover and put an end to Voss's plan.