Alex, a 12-year-old boy, and his friends fight an evil sorceress with the help of Excalibur, the sword of King Arthur, in a bid to save the world from her atrocities.
Old school magic meets the modern world in this epic adventure. Alex (Louis Ashbourne Serkis) thinks he's just another nobody, until he stumbles upon the mythical sword in the stone, Excalibur. Now, he must unite his friends and enemies into a band of knights and, together with the legendary wizard Merlin (Sir Patrick Stewart), take on the wicked enchantress Morgana (Rebecca Ferguson). With the future at stake, Alex must become the great leader he never dreamed he could be.
Alex, a twelve-year-old boy trying to survive school, has a chance encounter with destiny after pulling King Arthur's legendary Excalibur from the stone. As Alex unwittingly puts himself in harm's way, targeted by Arthur's evil half-sister Morgana, a race against the clock to save present-day England commences. However, mythical allies and unexpected supporters are on Alex's side. Now, there is no turning back. Will the kid who would be king prove his mettle and fulfil the peril-laden quest?—Nick Riganas
A long time ago, England was ruled by Oothur. When Oothur died, the land descended into chaos. As people fought over land, the country became lost and leaderless. In response, the Wizard Merlin conjured a magical sword called Excalibur and embedded it in a stone. Only Oorthur's true heir could remove the sword from the stone. Many tried over the ages, but only one succeeded and the boy was named Arthur. Arthur was a great King who turned his enemies into allies and ruled at a round table where everyone was equal. He and his Knights lived by a code of Chivalry with their hearts pure and noble.
Arthurs's greatest foe was his own half-sister, Morgana. Morgana was convinced that she was the rightful heir and desperate to posses the Excalibur, she turned to dark sorcery. Arthur and Merlin imprison Morgana into the bowels of the Earth after a fierce battle. Morgana vows revenge when Arthur is gone, and the land is again leaderless.
In the present day, global conflicts are rising, and the planet once again seems leaderless and without direction.Alexander "Alex" Elliot (Louis Ashbourne Serkis) is a twelve-year-old boy who is starting a new term at school while struggling to adapt to his new surroundings. When his best friend Bedders (Dean Chaumoo) is bullied by older students named Lance (Tom Taylor) and Kaye (Rhianna Dorris), Alex comes to his aid but ends up in a fight with Lance. Lance warns Alex not to be a hero.
Alex, Lance, and Kaye are given detention by the headmistress while she tries to encourage Alex to change his behavior and counsels him that the world is not going to change.Alex returns home to his mother Mary, who realizes that Alex was trying to protect Bedders and didn't tell that to the headmistress as he believed that it would make things worse. Mary tells Alex that telling the truth would never make things worse.
Meanwhile, Lance and Kaye plot to harm Alex further. That night, the duo chase Alex as he is on his way home but Alex hides in a nearby construction site, where he finds a mysterious sword and removes it from its position. Taking the sword with him, Alex shows it to Bedders, and they discover that its markings identify it as Excalibur, the sword of King Arthur. Alex refers to a book given to him long ago by his father, on the Knights of the Round Table. Alex finds that Arthur was from Tintagel. Alex says that he and his father once visited Tintagel and that was when he saw him for the last time.Alex then playfully "knights" Bedders.
Elsewhere, the wicked sorceress Morgana (Rebecca Ferguson) awakens underground. Through the water dripping down from the surface, Morgana had figured out that the humans are again divided, fearful and leaderless. As humans grow weaker, she grows stronger. Morgana realizes that the Excalibur has been drawn and sends her minions after the new King. Morgana needs the sword and for that she has to kill the King.
The next day, a teenager appears from inside Stonehenge and presents himself at Alex's school as a new student. Merlin is alarmed to learn that there is a total solar eclipse in 4 days' time. The boy reveals himself to Alex as the wizard Merlin (Angus Imrie), capable of aging backwards, but is also able to shift between his Arthurian counterparts like an owl. Alex plans to return the sword, wanting nothing to do with ancient myths.
That night, Merlin saves Alex from a demon (when Alex is attacked in his home, in his bedroom) and explains that he has four days to destroy Morgana, or she will enslave all of England. Morgana's demons can appear only at night and can only be seen by Alex and those he has knighted, but an upcoming total solar eclipse will enable her to emerge fully into the world. When Alex dithers, Merlin shows him a vision of the apocalypse that takes place once Morgana has control of the world.
Alex realizes that these events parallel an inscribed storybook his estranged father once gave him. Mary tells Alex that his father gave him the book so that he would grow up to be a good person, and not someone who would get into fights. Mary says that Alex's father battled his own "demons".
Merlin says that his energy gets depleted quickly at night. He needs beetle blood, vanilla, and ground animal bones for rejuvenation, which he all finds in modern processed foods.Alex concludes he descends from Arthur through his father and later recruits and knights Lance and Kaye, who fight beside Alex and Bedders, defeating three demons. Alex declares them a new Round Table. Merlin soon tasks Alex to find the entrance of Morgana's prison.
Believing his father is the key, Alex leads the group to Tintagel where he last saw his father. En route, Merlin trains them in swordsmanship. But when Morgana infiltrates the lesson, Lance betrays Alex and takes the sword for himself. Merlin barely saves them, and Excalibur is broken when Alex and Lance come to blows in a marsh. Alex calls upon the Lady of the Lake who appears and restores the sword.
Rededicating themselves to the quest, the four overcome a horde of demons by luring them over a cliff and arrive at Tintagel. Alex meets his aunt Sophie (Genevieve O'Reilly) who tells him that his father was revealed to be an alcoholic, a fundamentally bad person who abandoned Alex's family, and that it was secretly his mother Mary (Denise Gough) who inscribed the book. Alex is enraged to discover that not only has he come a long way for nothing but the fact that his mother lied to him about the book, and he starts to hate her for that. Merlin tells Alex that Excalibur is not handed down by birthright, but by individual merit.
Alex and his friends arm themselves and Alex uses the storybook to locate the entrance to the Underworld. Alex challenges Morgana who takes on a monstrous form and breathes fire, but Alex strikes her down and the children escape. Believing Morgana is dead, Alex returns Excalibur to the Lady of the Lake.
On the day of the eclipse, Merlin informs Alex that Morgana was merely wounded, and Alex realizes that he violated the Chivalric Code by lying to his mother. In desperation, Alex tells her everything that has happened. His mother reveals her own lie that she never told him the truth about his father or the book, because if he had known the truth to begin with, it would've hurt him. Eventually, he stuns her by summoning the Lady of the Lake into the bathtub, where he regains Excalibur.
At the school, Merlin enchants the faculty and Alex knights the entire student body. During the eclipse, Morgana appears with her entire army and now takes on a huge, semi-draconian form. The children fight back, using strategies combining medieval warfare with modern technology, but ultimately retreat to the rooftop. Merlin casts a magic spell to pull Morgana from the world and Alex decapitates her as she vanishes, dispelling all the demons. Alex, Bedders, Lance, and Kaye bid farewell to Merlin, who encourages them to become leaders. Alex once again returns the sword to the Lady of the Lake.
