Notorious but better-than-it-sounds science fiction novel by the equally notorious Jack L. Chalker. It posits a world in which Time Travel to or from the past is possible by "leaping" into the body of a person of that time. There is a catch: spend too much time in the past, and you'll "trip" and be stuck as that person permanently, even if you return to the present.
When the hero's first leap into the past uncovers a full-fledged war for control of the future, things go from bad to worse very, very quickly.
Predates Quantum Leap by more than a decade.
- Author Appeal: It is Chalker, after all.
- BrotherSister Incest: Guess what happens when you grow up on a desert island with no one but your parents and siblings for company?
- Butterfly Effect: Subverted: you have to kill someone really important before they'd accomplished their life's work to significantly affect the outcome of history. If you killed someone in the Middle Ages who was an ancestor of, say, Teddy Roosevelt, there'd still be enough genes in the pool for someone to give birth to Teddy Roosevelt hundreds of years later. History is like a big river and it "flows" around small impediments.
- Different for Girls: Specifically averted by The Mind Is a Plaything of the Body.
- The Dragon: Eric Benoni. He'd be the Big Bad but he works for a Bigger Bad in the form of a Politburo-style committee.
- For Want of a Nail: The protagonist turns out to be the nail. He's the mother of The Dragon. And it's implied that other time travel experiments also "failed" because their subjects were forcibly recruited into the time war by future time travelers.
- Gender Bender: Several, as you don't get to pick your target when you travel to the past.
- The Great Politics Mess-Up: Referenced as the antagonists are largely the inheritors of the old Communist block nations, who inherited the Earth by the simple expedient of waiting for the Capitalists to leave through planetary colonization. The Dragon, who has been given a relatively free hand in the time war, amuses himself by targeting Marx for a historical disruption.
- Hitler's Time Travel Exemption Act: Played with, though the historical figure in question turns out to be Karl Marx instead of Adolf Hitler.
- In Spite of a Nail: Played with: Killing Karl Marx before he publishes Das Kapital has a big effect on the time stream, killing him after not so much, and killing him shortly before he would have died anyway has hardly any affect at all.
- Meaningful Name: Eric claims his nom de guerre "Benoni" means "son of my sorrow" in Hebrew.
- Mental Time Travel: in effect but possibly not reality: Ontological Inertia causes each time traveler's personality to get inserted into a person of that time period. Whether or not that person actually existed prior to the time traveller's arrival is never made clear.
- No Ontological Inertia: Subverted. "Nightsiding" people (cutting them off from their prior selves) does not make them disappear or eliminate what they have done, but it does make them vulnerable to Ontological Inertia
- Ontological Inertia: Played with. Time does its level best to shunt time jumpers into insignificant people who can't or won't affect the timestream. And if you get nightsided, watch out, because time does not like loose ends.
- Ret Gone: The goal of the war is to do this to the enemy.
- Ripple Effect-Proof Memory: Subverted: you lose some of yourself (and gain some of the personality of your new host) every time you 'trip'. And if you spend too much time in the host's era afterwards you'll be totally assimilated. The heroes use an entire supercomputer just to keep track of the temporal logistics to prevent this from happening to their troops, and it means some people can't go on some missions because they'll exceed their exposure time.
- Disappeared Dad: The driving force behind the Dragon.
- Place Beyond Time: Not really, but the heroes' base is in the early Cenozoic, far enough back so plate tectonics will destroy all of the evidence.
- San Dimas Time: The "edge" in the future is always moving. The entire plot turns out to be a huge scheme to extend the edge long enough for people in the future to disarm the bombs their enemies had set as a booby trap. The huge, convoluted stable time loop was merely a distraction to give the people at the edge time to work.
- Screw Yourself: And have lots of children doing it, though by the point Dawn hooks up with her prior self Ron she'd tripped over as a woman several times and her earlier incarnation as Ron seemed less like a prior self than a fantasy lover.
- Set Right What Once Went Wrong: Played against Make Wrong What Once Went Right as each side in the time war monkeys with past events to gain momentary advantage in the future. A time agent might be ordered to kill Karl Marx on one mission only to get tasked with saving him later (later meaning some future point in the agent's own subjective history.) The protagonists are primarily distinguished from the antagonists in that they are reluctant to take the second course, though "wrong" and "right" are often subjective.
- Self-Made Orphan: Combined with Truly Single Parent and Even Bad Men Love Their Mamas in a way that only a Timey-Wimey Ball makes possible. Eric Benoni joined the antagonists because the protagonists sent his father Ron on a mission from which he never returned, not knowing (thanks to San Dimas Time) that Eric himself would be the antagonist who prevented his own father from returning, sending Ron on the stable time loop where he met and became Eric's mother Dawn instead. So Eric actually enabled his own birth and his own Start of Darkness in one twofer.
- Stable Time Loop: Used to "nightside" people by cutting them off from their prior selves.
- Start of Darkness: Eric Benoni started as the eldest child of protagonists Ron and Dawn (who are actually the same person, thanks to the story's combination of Stable Time Loop and Gender Bender, though neither Eric nor Ron were told that particular detail about his parentage) joined the antagonists because he blames the protagonists for the loss of his father. Subverted later when he captures Ron on a mission and learns that he's the reason his father never returned, making his Start of Darkness self-inflicted.
- Take a Third Option: The protagonists eliminate The Dragon through the simple expedient of reuniting his familuy before his Start of Darkness, severing that particular Stable Time Loop and nightsiding him.
- Temporal Paradox: Several. Both sides are either trying to cause them if they benefit themselves or smooth them out if they benefit the enemy
- Time Machine: Several variations and upgrades, from primitive "time suits" to more sophisticated belts and wristbands.
- Timey-Wimey Ball: And how. Justified — the rules of time travel appear to change around, but that's only because it's so poorly understood that nobody knows what the rules actually are. Combine this with improvements to the process and the technology, and things look especially inconsistent. That said, it still looks like a continuity snarl to the agents living through it because all of the intersecting time loops mean they often don't encounter the enemy, their fellow agents or even themselves in strict chronological order. Your next encounter might be in their subjective past, and thanks to "tripping" they might not be the same race or gender the next time you encounter them. One such incident resulted in Eric inadvertently nightsiding his own father who returned after several "trips" to become Eric's mother.
- Time Police: The hero is forcibly recruited.
- Truly Single Parent: Using a Gender Bender and a Stable Time Loop followed by Screw Yourself instead of cloning, but still...
- Unfortunate Names: Ron Moosic, the Hero. His grandfather, an immigrant with an unpronounceable name, renamed himself after the Pennsylvania city. IT proved an unfortunate choice.
- The War of Earthly Aggression: The time war proves to be a second front.
- Used to Be a Sweet Kid: The Dragon used to be the hero's eldest son—something neither of them is particularly thrilled to learn.
- Word of God: Chalker claimed that he wrote this story in an attempt to address the questions raised — but not answered — by Robert A. Heinlein's —All You Zombies—.
- You Already Changed the Past: Used, averted, and subverted as the hero experiences several time loops from various perspectives. Shows up initially when the protagonist learns that he is from the past and the real leading edge of time is hundreds of years in his future.
- Xanatos Gambit: The protagonists are playing for time, and even gave The Dragon his Start of Darkness because they knew he'd extend the war,