Power Trip was the first story-line to run in JSA: Classified, a companion title to JSA. Written by Geoff Johns – the writer of Infinite Crisis – it set out to solve the confusing origin of Power Girl.
Issue #1 Power Girl’s original (at least post-Crisis on Infinite Earths) origin is given; how she rocketed from the exploding Krypton and was found by her cousin, Superman. Revealed to the world as such, it was Batman who quickly found out she wasn’t Kryptonian and thus couldn’t be Superman’s cousin. As Dr Mid-Nite of the JSA runs tests on her, they discount her other post-COIE origin, that she was the grand-daughter of the Atlantean mage Arion. Returning to her Manhatten apartment, Power Girl is attacked by Garn Danuth, the brother of Arion; though she trashes her surroundings, by the time the JSA arrive to help, she is alone. Worryingly, the public claim that she had never been fighting anyone at all. In an abandoned theatre, a shadowed figure somehow materialises three members of the Legion of Super-Heroes: Cosmic Boy, Lightning Lad and Saturn Girl.
Issue #2 Trying to help Power Girl, Flash and Mr Terrific plan to examine the ship she came to Earth in but find it being examined by the government organisation, Checkmate where one of the scientists seems to find a Legion flight ring. Power Girl sits on the top of the Daily Planet building waiting to speak to Superman and is found by Jimmy Olsen. As the two talk, Cosmic Boy, Lightning Lad and Saturn Girl appear and try to convince her that she is actually Andromeda, a member of the Legion. While they talk, Power Girl spots a plane in trouble and attempts to save it but is kept from doing so by the Legion; fighting them off, she tries to help but Superman and Supergirl arrive just in time. As before, no-one saw her fighting with anyone and even Jimmy wasn’t there. In the abandoned theatre, the shadowed figure is revealed to be the Psycho Pirate.
Issue #3 In Gotham City, the Huntress fights against members of the Brotherhood of Evil who are looking for Chemo; unasked for, Power Girl flies in and helps her. She explains the problems she has been having with hallucinations and her powers fluctuating and, in need of a friend, sought out the Huntress. Flash and Mr Terrific, meanwhile, try to prevent Checkmate from taking Power Girl’s ship; the scientist who found the flight ring finds it changing into a golden mask as the Psycho Pirate materialises and manipulates the JSA heroes into fighting the Checkmate agents. Power Girl and Huntress talk until they’re interrupted by the arrival of the Crime Syndicate who claim that Power Girl is Ultraman’s cousin. Huntress, meanwhile, cannot see any of them other than Power Girl herself. One after another, other heroes and villains appear, all claiming Power Girl belongs to them. Eventually, her mind almost snaps and, as Huntress lays unconcisou, Psycho Pirate appears. After contacting Luthor to tell him he has her, Psycho Pirate takes Power Girl to where he ship lays and promises to tell her the truth.
Issue #4 Psycho Pirate tells Power Girl of her true origin which, ironically, is her original, pre-Crisis origin. She was born on the Krypton of the Earth-2 universe and sent to Earth to find her cousin, Superman. Psycho Pirate materialises the Earth-2 Huntress and Robin who ask Power Girl how she survived Crisis when they didn’t. The Pirate eventually leaves her alone and she returns home, still unsure of who she is and where she comes from. Psycho Pirate reports to Luthor and Power Girl is attacked by Clayface; the attack is continued in Infinite Crisis #2.
(It might be worth mentioning that the cover used above is the 2015 edition which includes not only the four issues of JLA Classified detailed above, but issues #1 to #12 of the later Power Girl series which is well worth a read.)