Timefall

It has been years since Joshua the Scribe, Lon the Vampire, Jasmine the Neuroman, and Beauty the Centaur journeyed to save their lost families from the strange Queen in the City With No Name. And as time went on, they were visited by ghosts of themselves, sometimes aiding in their quest and sometimes just a haunting presence. But were they really ghosts? Or were they simply incarnations of their own souls, visiting from another time to learn from them as well as to teach and to save their own world from the imminent destruction of the Timefall?
In this climactic denouement to the dystopian future envisioned in World Enough, and Time and Time's Dark Laughter, the first two books in this trilogy, a new Joshua and friends fall through a complex weave of time tunnels, landing in the terrain of the first adventures. But to their dismay, they discover that the fates of both times are interdependent, and the new world's Joshua must enlist forces from the old to save the whole tipping universe from extinction.