Batman #21 - "The Button", Part 1 - feels very much like a proper sequel to DC: Rebirth. We are very much in Geoff Johns' territory here. So much so that: a) I actually want to read Flashpoint again now; and, b) King's own ongoing storyline doesn't even get a throwaway reference.
Jason Fabok's artwork is outstanding here; just really, really good. There are some deliberate callbacks to Watchmen here. Ironic, considering it took me 10 minutes to read from cover to cover; an issue of Watchmen would take me a lot longer than that!
The story, however, has barely got started by the final page, so there's no real indication of how much is finally going to be revealed, or not, at this time. Hopefully we'll get some more forward momentum in next week's Flash.