Enredo

A poor boy named Arthur learns the power of love, kindness, knowledge and bravery with the help of a wizard called Merlin in the path to become one of the most beloved kings in English history.

Arthur (aka Wart) is a young boy who aspires to be a knight's squire. On a hunting trip he falls in on Merlin, a powerful but amnesiac wizard who has plans for Wart beyond mere squiredom. He starts by trying to give Wart an education (whatever that is), believing that once one has an education, one can go anywhere. Needless to say, it doesn't quite work out that way.—Tim Pickett <quetzal@yoyo.cc.monash.edu.au>

The kingdom of Britain has, for years, remained divided. Wart, a measly servant knave, dreams of becoming a knight but is barely certain he may act as squire to castle lord Sir Ector son Kay; then, the sorcerer Merlin and his grumpy, talking owl Archimedes invite themselves to the studio and move into the north tower. Merlin, who can magically access the future, intends to prepare Wart for a grand future, so he gives the squirt dangerous lessons, transforming themselves into animals to learn the mental skills befitting a knight and a ruler. Since the once-renown magical sword in the stone that could confer the kingdom of all England unto one person (thus unifying it) has never been able to be withdrawn for years, a tournament in London is formed to designate a ruler instead. Kay is going to compete, but the rude, lout stands no chance.—KGF Vissers

After the King of England, Uther Pendragon, dies without an heir to his throne, no one can decide who is the rightful heir to the throne. With war threatening to tear the country asunder, a stone and anvil appear from the heavens in London town, with a sword planted firmly in the anvil. The sword has an inscription proclaiming that whoever removes it will be the future king. Many have unsuccessfully attempted to remove the sword, and the sword becomes forgotten, leaving England in the Dark Ages where the strong preyed upon the weak.

Merlin, the Wizard, calls it the Dark Ages as there is no electricity, no plumbing and a lot of inconvenience, suggesting that he can time-travel. Merlin is waiting for someone to arrive, although he doesn't know who. Merlin says that fate will direct the person to him, and he will guide the person to his rightful place in the world.

Years later, an 11-year-old orphan named Arthur (Rickie Sorensen, Richard Reitherman, and Robert Reitherman), commonly called the Wart, accidentally scares off a deer his older foster brother Sir Kay (Norman Alden) was hunting, causing Kay to launch his arrow into the forest. Kay is a well-built fellow of 20 years of age, while Arthur is a scrawny looking boy.

While retrieving the arrow, Arthur meets Merlin (Karl Swenson), an elderly wizard who lives with his talking pet owl Archimedes (Junius Matthews). Merlin is horrified to learn that Arthur is training to be a Squire and has had no real education at all. Merlin decides to accompany Arthur back to his home and after packing up everything in the hut into a small satchel, the two set off.

Merlin declares himself Arthur's tutor and arrives at Arthur's home, a castle run by Sir Ector (Sebastian Cabot), Arthur's foster father. Merlin introduces himself and Archimedes to Ector and displays his powers to the doubting lord. Merlin says that he is the world's most powerful wizard and has come to educate Arthur. After some persuasion, Ector allows Merlin to stay, putting him up in the Northwest Tower, a crumbling edifice of the castle. Merlin threatens Ector that if he is evicted, he can always terrorize Ector with his magic. The Northwest Tower leaks during the rains and is not protected from the cold, harsh winter, but Merlin decides to stick it out.

Ector's friend, Sir Pelinore (Alan Napier), arrives to announce that the winner of the upcoming New Year's Day tournament in London will be crowned king. Ector decides Kay will be a contender and appoints Arthur as Kay's squire.

Merlin hears of this news and decides to push Arthur to see his true potential. Merlin can move into the past and the future, he knows who Arthur will become. To educate Arthur, Merlin transforms them both into fish. They swim in the castle moat to learn about physics. Merlin shows Arthur how every movement of the fin creates a corresponding equal movement in the opposite direction. Merlin tells Arthur that a water world also has its jungles and forests. This goes on until an angry pike attacks the pair. Merlin asks Arthur to use his brain to defeat the pike. Arthur takes a broken arrow and lodges it in the jaw of the pike. The pike breaks through the arrow and chases Arthur, who is only saved by the quick reaction of Archimedes.

After the lesson, Arthur is sent to the kitchen as punishment for attempting to relate what happened to Ector and Kay. Merlin enchants the dishes to wash themselves, then takes Arthur out again for another lesson.

For the next lesson, Merlin transforms them both into squirrels to learn about gravity. Arthur almost gets eaten by a wolf, but is saved by a female squirrel (Ginny Tyler) who falls in love with him. The female squirrel fights the wolf on her own, to save Arthur from being eaten by it. Merlin informs Arthur that when a girl squirrel chooses a mate, it is for life. Merlin himself is chased by a fat female squirrel and cannot be rid of her. Merlin has enough and turns himself and Arthur back into their original forms to scare away the squirrels.

Back at the castle, a panicking maid warns Ector and Kay about the kitchen being under a spell. Kay and Ector immediately arrive at the kitchen where they prepare to do battle on the enchanted dishes, trying to undo the spell. However, they fail and get beaten by magical dishes and appliances. After they return to human form, Ector accuses Merlin of using black magic on the dishes. Arthur defends Merlin, but Ector punishes Arthur by giving Kay another squire, Hobbs.

Resolving to make amends, Merlin plans on educating Arthur full-time, but Merlin's knowledge of future history confuses Arthur. Archimedes interjects on Merlin's teaching methods, as Merlin is educating Arthur on things that will not be proven for hundreds of years and could very well lead people to think of Arthur as a raving lunatic in their current Dark Ages.

This prompts Merlin to appoint Archimedes as Arthur's teacher. Merlin transforms Arthur into a sparrow and Archimedes teaches him how to fly. Soon after, Arthur encounters Madam Mim (Martha Wentworth), an eccentric, evil witch who is Merlin's nemesis. Madam Mim playfully shows Arthur her magic powers, which are more so for evil purposes. As Arthur explains more about Merlin and his magic, Mim decides to 'destroy' the little bird. Merlin arrives to rescue Arthur before Mim can destroy him, and Mim challenges Merlin to a wizards' duel. Despite Mim's cheating, Merlin outsmarts her by transforming into a germ and infecting her, illustrating the importance of knowledge over strength.

On Christmas Eve, Kay is knighted. When Hobbs comes down with the mumps, Ector reinstates Arthur as Kay's squire, which spurs him to happily break the news to his teachers. Archimedes congratulates him, but Merlin, thinking Arthur is forsaking education, rebukes him for staying under Kay's thumb. When Arthur retorts that he's lucky, Merlin angrily transports himself to 20th-century Bermuda.

At the tournament, Arthur realizes he left Kay's sword at the inn. It is closed for the tournament, but Archimedes sees the "Sword in the Stone", which Arthur removes almost effortlessly, unknowingly fulfilling the prophecy. When Arthur returns with the sword, Ector recognizes it and the tournament is halted. Ector places the sword back in its anvil, demanding Arthur prove that he pulled it. He pulls it once again, revealing that he is England's rightful king, earning Ector and Kay's respect and the former's apology.

Later, the newly crowned King Arthur sits in the throne room with Archimedes, feeling unprepared for the responsibility of ruling a country. Merlin returns from Bermuda and resolves to help Arthur become the great king he has foreseen him to be and ensure his legacy.