During the Middle Ages, all of Britannia trembles at the name of the vicious warlord, Arthur of Camelot (Neill Rea). When Arthur is about to claim the throne, his centuries-old teacher, Merlin (Norman Forsey), appears to denounce Arthur's violent ascension and to teach him a lesson about leadership. As Arthur attempts to draw Excalibur from the stone, Merlin sends Arthur a thousand years back in time. Unfortunately, Arthur's advisor, the evil sorceress Mab (Sara Wiseman), goes with him.
Back in the Greco-Roman world, Hercules (Kevin Sorbo) is approached by a young British man (Tim Faville) who introduces himself as Merlin. He asks Hercules if he would like to save millions of lives, if he has a free moment. Hercules completes his task and agrees to go. Merlin has had visions of events in Britannia and believes that Hercules can help. When Hercules and Merlin disembark on the island, they are surprised to find Morrigan (Tamara Gorski). A heartless new leader is ruling the Britons and Morrigan wants take care of the problem before this ruler's quest for power leads him to Eire.
Arthur has made the best of his time in the past, quickly conquering the "savages" of Britannia, but Mab is impatient to return to the "civilized" dark ages. She believes that if they can find the young Merlin and kill him, they will be sent back to their own time. Unfortunately, she needs the power of Excalibur to kill Merlin. Mab escorts Arthur to collect Excalibur from the Lady of the Lake (Asa Lindh), who is surprised to see him a thousand years before his time. As they return to the castle, Arthur and Mab attack Hercules and his friends. Hercules manages to relieve Arthur of Excalibur, while Merlin surprises himself by deflecting one of Mab's energy bolts. Mab escapes with Merlin, while Hercules and Morrigan capture Arthur. Morrigan is anxious to kill Arthur for the horrible things he has done, but Hercules believes Merlin sent Arthur back to be reformed. Slowly, Arthur begins to respect Hercules.
Mab, unable to kill Merlin without Excalibur, interrogates the wizard, who is constantly shocked by the growing evidence of his magical powers. When Hercules finally locates Mab, he tells her that Arthur is dead, and she reveals that she never cared about Arthur and only wanted Excalibur. Arthur, stunned at learning the truth, steps out of the shadows and Mab is angry at being caught. She sends a giant knight to attack Hercules and his friends. Arthur uses his newfound heroism to save a child and Merlin uses his powers to smite Mab, while Hercules dispatches the monster. Hercules places Excalibur in the stone, and a reformed Arthur returns to his own time to usher in a new era of peace and thanks his old friend, Merlin, who has waited a thousand years to see it.
Starring: Kevin Sorbo (Hercules)
Guest Starring: Tamara Gorski (Morrigan), Neill Rea (King Arthur), Sara Wiseman (Mab), Tim Faville (Merlin), Norman Forsey (Old Merlin), Asa Lindh (Lady of the Lake), Michael Garnet-Holt (General Gwain), Wayne Peters (Albion), Emlyn Williams (Trevin), Graham Smith (Baker), Andrea Bruce (Teacher), Steve Isherwood (Soldier #1), Wayne England (Soldier #2), David Holton (Knight #1)
Written by Gene O'Neill & Noreen Tobin
Directed by Mark Beesley
Trivia: This was the 100th episode filmed of "Hercules: The Legendary Journeys".