Killers of Krypton

"Mourning the loss of the Kryptonians wiped out by Rogol Zaar, Supergirl decides to play detective and sets off into deep space to learn more about the would-be usurper. Superman and Supergirl, the last two Kryptonians on Earth, have had their beliefs shattered. With new revelations about their home planet--and the man who destroyed it--Supergirl builds a star cruiser using whatever tech she can scrounge, and after intel from Green Lantern, she blasts off into the cosmos with Rogol Zaar's deadly axe to solve the mystery--along with a traveling companion you won't believe!"--