Excalibur

In Arnwin, a parallel world known to us through British legend, the peace and prosperity that followed the creation of the new Kingdom of Albion is threatened by a plague spreading across the nation. The situation only gets worse when it is discovered that the source of the disease is probably a group of thieves sent from the legendary Otherworld by Albrecht, the disgraced former High Priest of the Chrysteon Church.

Realising that this is probably a precursor for a full invasion using the terrible weapons known to exist in the Otherworld, the reluctant King Owain agrees to send a party between the worlds to stop his enemy. When his own son falls ill, he's persuaded to follow the raiders to seek a cure.

Owain soon finds that Albrecht has already become a target for police and security services on both sides of the Atlantic who believe that the Sidhe who died pursuing the High Priest were extra-terrestrials, and he and his friends are quickly captured. Their objectives of eliminating Albrecht and keeping the secret of Arnwin safe seem doomed, especially as Albrecht remains free.

However, Gareth Thomas, a disillusioned Welsh detective, already knows the secret of Arnwin and rebels against his superiors. Even with Thomas' help, Owain needs to fight his own self doubts and overwhelming odds if he is to save his world.