In a fourth-season arc Clark, instructed by Jor-El, searches for three Kryptonian stones which contain the knowledge of the universe and form his Fortress of Solitude.
Dalam busur musim keempat, Clark yang diinstruksikan oleh Jor-El, mencari tiga batu Kryptonian yang berisi pengetahuan tentang alam semesta dan membentuk Fortress of Solitude.