A genealogy investigation and a knock on the head takes Mac back to King Arthur's court, where he must use his knowledge to prove Merlin innocent of harming the King, find the fair Cecilia and foil Morgana's attempt to take over the throne.

A genealogy investigation and a knock on the head takes Mac back to King Arthur's court, where he must use his knowledge to prove Merlin innocent of harming the King, find the fair Cecilia and foil Morgana's attempt to take over the throne.

A close friend of MacGyver is murdered. In searching for a reason for this assassination, MacGyver discovers a secret nuclear weapons plant right in the center of Britain.