After rereading book two of Piers Anthony's Incarnations of Immortality, Bearing an Hourglass, I got a sterling reminder of how much of a headache it is. Not that it isn't fairly well written, but the set up is involved.
We start with Norton, who's more or less an uninvolved drifter, living in different wilderness areas on and off. He's approached by a ghost, Gawain, who needs someone to sire his heir. Seems Gawain died fighting what he thought was a dragon, but was really a dinosaur, and he died without a child. As such, his family married the ghost to Orlene, who is supposed to bear a child to continue the line. Enter Norton.
Norton and Orlene do hit it off, and she indeed bears a child, Gawain II. However, Gawain I made arrangements with Gaea to make the child a true heir, which includes some vaguely defined genetic defect that causes the baby to die before a year. (As I recall, this gets better defined in Book 8.) Thanatos does show up and explain the situation to Norton, which doesn't help when Orlene commits suicide in her grief later on. Gawain does attempt to get Norton to provide stud service with the new ghost wife, but it doesn't happen. Eventually though, Gawain does get Norton into the position of Chronos, Incarnation of Time, as a way of apologizing for getting him into the situation in the first place.
Chronos has issues, not the least of which being her travels backwards in time in relation to everyone else. In other words, when Norton takes the Hourglass, his natural progression is now from the moment he took the office until he reaches his birth or conception. As such, he takes the office roughly twenty years after the events of On a Pale Horse, but before the events of And Eternity. (As I stated at the outset, the timeline in the series is a bit wonky. Chronos makes it even worse.)
Anyway, Norton gets an offer from Satan that leads to a changed timeline, and Norton has to go fix it. Satan gets mad and keeps throwing Norton into what he claims as contraterrine worlds, made of antimatter, where time runs the way Chronos lives. Which leads to three really cheesy adventures involving Bug Eyed Monsters and Alicorns.
Oh yes, and Orlene give Norton Sning, a snake ring that can answer yes-or-no questions as well as indicate the passage of time. And other things. Sning is awesome.
The problem is, a later part of the book involves a really involved explanation of General Relativity, which, while presented in ways to make it easier to understand, still is just as lofty and migraine inducing as the 10 page chaos theory explanation in Jurrasic Park.
Still fun to read after all these years, and I remain amazed at how many clues to other volumes are hidden within.