So, Power Girl falls from the sky in Earth-2 (where she was sent by Gog) and is found by Huntress (Helena Wayne). After bringing PG in for treatment and revives, we find out that the Earth-2 Justice Society and Infinity, Inc. have merged into Justice Society Infinity (JSI), with mostly Infinity, Inc. characters, many of whom are dead on "New Earth". In the subsequent discussion, we find out that Karen went to look for the missing Superman and Lois several years back, and this is the first they've seen of her since. She tells them the bad news from the Middle Crisis, which they have no knowledge of.
However, they do remember the parallel earths and red skies from the First Crisis, and had thought all other universes had been destroyed in it (which they were, just not in the way that they think). Lyta Trevor-Hall (Wonder Woman's daughter on Earth-2) says "Thank the gods they weren't. Mother will be so pleased." A telling clue for later...
Spectre and Dr. Fate (the originals!) come across each other near the scene of PG's fall to earth, and realize that the multiverse has reared its head again, and fear the consequences.
Karen can't sleep and encounters Helena, who is looking for the Joker, who tried to turn DA Harry Sims (Helena's bf) into a new Two-Face (the old one is dead) and apparently killed Alfred as well. They find him. Helena gets ready to kill the Joker, but Karen steps in first and Joker is electrocuted by the feedback one of his gimmicks.
Afterwards, Helena confesses that just before the Joker had intervened, the DA had proposed to her at some type of party (shades of "Dark Knight"!) and she was about to turn him down - because she's really been in love with Dick Grayson (Robin) all her life. After some nice bonding moments - another Power Girl appears! This one verifies her identity as the "real" PG (who never found her cousin), and by the end of the story the entire active JSI (17 members!) is hunting down the New Earth version. To be continued in the pages of the regular JSA comic...
Comments: A telling moment was when Lyta mentioned her mom, because the Earth-Two (pre-First Crisis) Wonder Woman left our plane of reality, during the Middle Crisis. No, Earth-Two and Earth-2 (the current one) are two different Earths, and the Karen who has been on New Earth was from Earth-Two. Which means that the Superman and Lois of Earth-2 might still be alive...that, and the Huntress-Robin subplot are likely to be resolved during the JSA Earth-2 story arc.