London, England. An old man is attacked by three street punks as he prepares to leave for Cornwell. Fighting like a professional he repels and defeats them, capturing one of them who he asks to take him to his leader. They arrive at a dark esoteric shop where a lady amongst shades is waiting. We soon discover that the old man is Lancelot, knight of the round table and the woman is his old time enemy Morgan Lafey. They were both condemned to live for eternity.
Morgan tells Lancelot why he was in such a hurry to reach Cornwall, Merlin who had been in a deep sleep for hundreds of years was summoning him. Morgan felt that he should be cautious as she always had thought Merlin was a manipulative old man. With her magic she transports Lancelot and one of the punks to the cave where Merlin is sleeping.
They revive Merlin with an elixir. Merlin after centuries of sleeping is in good shape and proves to be a manipulative being. He wants to bring back the king to the throne of England and change the world to his own liking. They are all led outside the cave by Merlin into the druid temple of Stonehenge.
Not wanting to be in any of Merlin's evil plans, Lancelot, challenges him to a duel. He has to confront an old knight's empty armor which guarded Merlin's cave. A black armor is magically created for Lancelot to wear but for Merlin's surprise, Lancelot is no longer a slow-aging man for he had taken himself some of the reviving elixir given to Merlin.
During the fight it seems Lancelot is going to win. Merlin tries to play dirty by using his magic powers to which Morgan (who had previously appeared in the cave to observe the battle) uses her own magic to try to stop Merlin, although it was not enough cause she falls back and lies severely injured. Thanks to her help, Lancelot finally defeats the evil armor and breaks Merlin's magical staff, his life is spared, and in the end he disintegrates.
Lancelot has a conversation with Morgan before dying, where she informs him that they would be back in London if they take the right path when leaving. While walking back he spots a road to the left which leads to a shining castle to which he decides to wander off and the punk, after a brief moment of thinking about it, decides to follow him.