It's the aftermath of the "Reality Lost" arc as Booster Gold learns the dire consequences of time travel from Time Master Rip Hunter. And the toughest lesson learned involves understanding how keeping his sister Goldstar alive could be more dangerous than anyone ever dreamed.
Booster gold finds himself in anchient Egypt with a version of himself from a different time period. The two Boosters are arguing over who is the better Booster when an angry mob of egyptians chase them. When they get back to the time Sphere they find some egyptians guarding it so they create a devergsion and break into the time and sphere and head to vanishing point to find Goldstar.
Meanwhile at Vanishing Point Goldstar has discovered she isn't suppose to be alive and feels like she's been treated like a child. She deactivates Skeet and takes the time portal so a new time and place.
Once the Boosters find out that Goldstar ran away they return one Booster back to his own time, and save Rip from when he was. Booster explains to Rip that Goldstar is gone but he fixed the time stream once again.