The apocalypse is over, adam went back to being normal, heaven and hell left aziraphale and crowley alone and they got married. But this story isnt about them. Its about a technical 25 (7000) year old with gender identity problems and is pretty much dating the archangel gabriel when god tells them "im giving you custody over the antichrist because hes your half brother, ok byeee" so now its their job to take care of the literal antichrist (there will be a sexual reference in every chapter, some strong, some vauge)

1000 years into the creation of the earth, Beelzebub is sent to replace an incompetent demon and take over his job of tempting the pharaoh of edgypt However, a certain angel is sent to stop them