Release Message:  Knights from a parallel universe arrive on Earth to find the legendary sword Excalibur. And only the Doctor and Ace (Sophie Aldred) with the assistance of Brigadier Lethbridge Stewart and save the Earth from total catastrophe.

Description:  Knights from a parallel universe arrive on Earth to find the legendary sword Excalibur. And only the Doctor and Ace with the assistance of Brigadier Lethbridge Stewart and save the Earth from total catastrophe.