After Jo Mullein is given the power of the Green Lantern by a dying Abin Sur, she would soon face the arrival of the space warlord Mongul as he seeks to turn Earth into his new Warworld, turning her home city into a twisted battlefield where might makes right. Jo, with the help of Superman and their allies, face Mongul's warriors as they search for a way to stop the invasion before Earth becomes an unrecognizable hellscape.
