Download or read book Supergirl (2016-) #21 written by Marc Andreyko and published by DC Comics. This book was released on 2018-08-08 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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. Using whatever tech she can scrounge, Supergirl builds a star cruiser, and after intel from Green Lantern, she blasts off into the cosmos with Rogol ZaarÕs deadly axe to solve the mystery-along with a traveling companion you wonÕt believe!