Supergirl #18

THE HEIR OF EL! After the battles in Kandor and El Caldero, Supergirl has now achieved a reputation as the Heir of the House of El. Granted access to a Fortress all her own, she and the Super Force are excited to move in and explore their new home base. But for weeks Supergirl's been hearing a mysterious voice calling out to her, and that being is now ready to make itself known.