After the events of The Totality, Martian Manhunter, John Stewart, and Kendra Saunders, fly to Thanagar Prime to seek out the aid of the Martian Elder, known as The Keep, who is being safeguarded in the Thanagar Prime Vault. The hope to be able to speak to her about the Totality and what it means to the Universe that it has returned.
Once on Thanagar Prime, the three Earth Heroes are met by Shayera Hol, who is now Ruler of Thanagar Prime, and she informs them that The Keep is dead. She also attempts to read Kendra's Nth Metal wings but can not desifer they meaning nor explain how she and Kendra exist in the same Universe. Shayera invites the heroes to stay awhile and join the her at a party that evening. Not fully trusting Shayera, the heroes except.
That night at the party, Manhunter learns through telepathy The Keep isn't dead, but is being held against her will. The heroes met up to discuss what to do next but are ambushed by Sheyera, her Wingman Guards, and a seeming mind controlled Katar Hol.
The heroes escape due to Manhunters abilities to alter peoples minds, and regroup. They then break into the Vault to seek out The Keep. Manhunter is able to locate her, but not before the Sheyera learns about their plans, and the heroes are forced to fight Sheyera, Katar, several WIngman, and a small band of Green Lanterns lead by Kilowog who have been sent by Oa to arrest John Stewart for crimes against Thanagar Prime. A battle breaks out and Manhunter slips away to speak with The Keep.
Manhunter learns The Keep is being held by The Absorbascon, a device that takes The Keeps mental powers, amplifies them and makes new pockets of realities, like Thanagar Prime. He then learns that the Keep knows all about the Totality and how is a piece of the Universe before this one. He learns that because of him the Totality may be able to cross time and space into this Universe.
Then when The Keep dies, Sheyera tries to use the Absorbascon herself to keep Thanagar Prime together but Manhunter shows her the errors of her ways. Sheyera feels remorse but now it's too late and the Vault is sealed with everyone trapped inside.
Meanwhile on Earth, Batman attempts to use Starro to unlock the information that is trapped inside an unconscious Starman. Batman almost glimpses the true nature of the Totality but Superman and Wonder Woman arrive and stop the experiment before it kills Batman. This does cause Starman to overload with power and it appears like he may explode and destroy the Earth, but Wonder Woman uses her Magic Lasseo to get him under control.
Starman then explains they must to head to Thanagar Prime and help Hawkgirl and then teleports them across the Universe. Starman, Batman, Superman and Wonder Woman find Hawkgirl and the other heroes trapped in the Vault, Starman frees everyone, returns Shayera's soul back into Kendra, and explains that she is now complete and is destined to fix the Source Wall.