Lok and the Foundation team are on the trail of Avalon. Sophie is drawn to a crystal cave where she must prove herself to the Casterwill Elder Nimue. Sophie learns she is a direct descendant of Lord Casterwill and bonds with the titan she thought was lost, empowering her and turning her into Powerbonded Sabriel. Nimue promises to help her find Avalon and the Willblade.
