Kara In-Ze was the only survivor from Krypton's sister planet, Argo. While exploring the sector of space once occupied by Krypton, Superman discovered a hidden cryogenic facility which had sustained heavy damage. Only one chamber was intact, containing the last survivor of Argo: Kara. Taking the young woman back to Earth, Superman introduced Kara to his adoptive parents. The Kents took her in for three years, isolated from the world at large under Clark's instructions, in the guise of Jonathan Kent's teenaged niece.