Levitz, Staton and Layton give Power Girl the lead in the Justice Society story from All-Star Comics 67 (July/Aug 77).
Picking up from the end of the previous issue, Power Girl argues with Wildcat and the Star-Spangled Kid about investigating the mysterious pit in Alaska. Power Girl figures that it must have something to do with why the Injustice Society came there in the first place. Some creepy creature emerge from underground, and though Kid wants to fight them off, Power Girl insists they allow themselves to be captured, in order to go down and explore.
She sends off a JSA alert, which is received by Flash, Hawkman and Dr. Fate, who are with Robin in South Africa. I ought to have mentioned that, in the last issue, they brought Hourman there for medical attention. Hawkman and Flash head off to answer the summons, while Fate has a different direction in mind.
He heads back to Gotham City, to confront Bruce Wayne. Wayne demands answers about Green Lantern's rampage, but Fate just tells the commissioner that there is more going on than Bruce is aware of. That doesn't go over well, and Wayne orders the police to arrest the Justice Society.
Flash and Hawkman join the Star-Spangled Kid and Wildcat in the underground civilization, but it's Power Girl' show all the way, as she battles and defeats the creatures who have been plotting to conquer the surface world.