Arthur has fallen, and his passage into Avalon has flung Britain into darkness and despair at the hands of his wicked half-sister, Morgana. After striking an alliance with Gwyn ap Nudd, Lord of the Underworld, Morgana has named herself empress, and seeks to gain control, not only of the mortal realm, but of Avalon and the Otherworld as well. With the help of the soulless Black Knight, she is able to steal the mystic Blue Rose from Avalon, and strip the Lady of the Lake of almost all of her power. The Lady of the Lake, left with no other option, uses her waning magic to call Merlin out of his prison, instructing him to recover Sir Gawain from his own captivity in Limbo. Together, they must awaken Arthur from his twenty year sleep, for Arthur alone has the strength to rescue Avalon and restore balance to all worlds before Morgana completes her domination.