Four young knights, Rohan, Deirdre, Angus and Ivar, defend their ancient homeland of Kells from attacks by the evil Queen Maeve who is intent on ruling the island kingdom. The knights bravely resist Maeve's dark sorcery, battling giants, ogres and evil mythical creatures. Their quest to restore peace to the land leads the knights to discover their mystic armor and their dragon ally, Pyre, who joins them on adventures filled with danger, magic, and the roguish little people who inhabit the enchanted underworld of Tir Na Nog.
Maeve launches a full on attack on Castle Kells that forces the Knights and Conchobar to retreat.
Contemplating leaving Kells, Rohan decides to stay and fight as Garrett returns to aid in the battle.
Rohan faces Lugad one on one and makes a stunning discovery that links them together.
Lugad helps turn the tide of war for Temra as the Knights must figure a way to stop him. Rohan undergoes a dangerous test to gain the powerful Battle Fury armor.
As the war turns against her, Maeve pulls out her secret weapon that was bred by her teacher Nemain: Lugad, a monstrous warrior.
Maeve awakens an ancient warrior who uses a scepter to take over the minds of Kells soldiers and the Knights.
Maeve resurrects the legendary warrior Balin and sets him against Kells, forcing Rohan to battle his idol.
Maeve casts a spell on Rohan that makes him doubt in his abilities and weakens him in battle.
A beautiful princess named Lynette is found on the shores of Kells without her memory by Fin Varra's scouts. Garrett grows closer to her while her arrival coincides with the monstrous Grindon attacking.
A young prince who seeks to have his kingdom ally with Temra comes to claim it and the Knights must keep him safe, despite his bratty attitude.
Jealousy of Rohan's prominence leads Angus to a falling out with his friend.
The Knights must find the kidnapped Fin Varra before Maeve steals his powers.
After saving a wood elf, Angus is offered one wish and the other Knights pressure him to use it for their own desires.
In order to stop a storm of dark magic, the kings of Kells and Tir Na Nog must switch places for a day. While Conchobar organizes the fairies into a fighting force, Fin Varra's more fun ways with the Kells soldiers leave them vulnerable to attack.
Conchobar is taken by a visiting lady but Deirdre senses something wrong about her.
Ivar finally manages to steal back his people's chalice from Torc. However, the chalice is Mider's link to the dark realms and taking it back to Ivar's kingdom is too dangerous. Ivar decides to take the chalice anyway but is captured by Maeve while Mider is left stranded at Castle Kells.
Entering Tir Na Nog, Torc steals a powerful weapon that allows him to challenge the Knights.
Tricking Cathbad into turning him human-sized, Mider overthrows Maeve and becomes ruler of Temra. Realizing the power-mad fairy is a more dangerous threat, the Knights aid Maeve in taking back her throne as the answer to King Fin Varra's advice.
Rohan and Deirdre work to clear Angus when he's accused of robbing villagers and vandalizing their properties. While Ivar is busy looking for the real culprit, Maeve summons a fire monster and sends it to Kells.
Ivar is told the story of how Angus and Rohan became friends as children as well as how Torc joined with Maeve.
When the Northmen, a race of savage invaders, kidnap Conchobar and threaten the whole island, the Knights offer a truce to Maeve to fight them off. However, the invasion is all a ruse of Maeve's to take over Kells.
The Knights discover a dragon's egg in the forest and must keep it from Maeve. Meanwhile, Angus falls in with some old thief friends of his, and Deirde and Garrett attempt to work out their relationship.
Garrett must overcome his arrogance in order to become the new Mystic Knight when he fights a giant spider in Banshee Woods. While Garrett is tangling with the giant spider, Mider summons four of the Spectres of the Banshee Woods to fight the other Knights.
Told that Garrett is important to the future of Kells, the Knights manage to free him from his spell.
Maeve uses a spell on Garrett to turn him into her fighter. He soon manages to defeat the Knights and steal their weapons.
In order to forge an alliance, Conchobar agrees to marry Deirde to Garrett, a prince of another land. His arrogance soon rubs all the Knights the wrong way and they tell him to leave.
On an errand for Cathbad, Deirde drinks from a magic pool that turns her into a hag. When she goes to Fin Varra for help, he's taken by her new appearance and shrinks her down to be with him.
A messenger from Ivar's home requests his return as news comes of a new Temra attack. Both are part of a plan by Maeve to separate the Knights while she uses sleeping fog to take over Kells.
Aideen accepts a spell from Maeve that turns her into a human so she can pursue Rohan. Maeve uses the opportunity to capture Deirdre, forcing Aideen to choose the princess or her new form.
Maeve takes advantage of a Kells holiday to send ghostly creatures to attack.
When Conchobar is taken ill by a spell in the form of a gift, Deirdre must become Queen in his stead. However, her worry about making the wrong choices pushes her to accept a challenge from Maeve that could spell disaster.
Cathbad's druid teacher Seethchenn comes to Kells and seems to help the king making Cathbad feel unneeded. However, when it's discovered the druid is working for Maeve, Cathbad must overcome his doubts and fight his mentor.
Taking what she thinks is a potion to boost her strength, Aideen turns Deirde into stone and must undo the spell.
Maeve and Torc trick Rohan into reciting an incantation and bring the ancient dragon Tyrune to life.
Mider tricks the Knights into giving up their weapons as he takes over Tir Na Nog.
Pyre reveals that Rohan himself is Draganta, which he is uneasy about. Maeve takes advantage to cast a spell that turns the other Knights against each other.
Maeve has her soldiers kidnap Angus to keep him from facing the Rock Wolf of Temra. When his friends rescue him, Angus confronts the Rock Wolf while the others fight the Bull of Temra.
Ivar battles the Sea Serpent of Temra for his armor and his feelings about being in Kells. Meanwhile, the others protect a village from a Cyclops.
Deirde faces the Lightning Bat of Temra for her suit of armor. Meanwhile, Maeve tricks Rohan into thinking that Temra wants peace with Kells so that she can sic the Tash Hound of Temra on him.
The Knights fail to tame Pyre the fire dragon and realize they need their armor to do so. Rohan is first, defeating the Ice Lord of Temra to gain his armor and then assisting the others in fighting a juggernaut.
In the fairy kingdom, the Knights are put through a series of tests to find their worth. Once they prove themselves, they are granted the Mystic Weapons which they use to fight back a Temra attack.
When her plans for war on Kells are revealed, Maeve begins to raise a monster to battle Kells troops. Told of the ancient scroll which can find Draganta, Rohan and Angus are on the trail, meeting with Ivar along the way. Deirdre follows as the four fall through a portal in the earth.
