Acting on information from their father, Alex and Cleo enter a myth chart program onto the computer and discover that there are missing links that should be there. Alex goes into the myth hoping to find the Gorgos stone, but instead discovers that the myth is collapsing upon itself and the Gorgos stone is to blame. Barely getting out on time, they realize that the Gorgos stone is responsible for the missing myths and that if they don't do something to stop it, the whole world might change.
Using the information from the computer, Cleo plots the trajectory of the Gorgos stone and discovers where it will be next. Even though Alex warns her against it, Cleo goes in and becomes the Lady Blodeuwedd, who may or may not have murdered her husband with the help of her lover. With the sentence of death hanging over her head, and no idea of what really happened, Cleo must prove her innocence with only the help of her lawyer when even her dead husband is testifying against her.
