Science-fiction series by Richard C Meredith, about TheMultiverse, consisting of ''At The Narrow Passage; No Brother, No Friend'' and ''Vestiges of Time''.

Eric Mathers is a Timeliner, an employee of an alien species called the Krith, who have developed the ability to "skud" between timelines. Using this ability, the Krith have built a substanstial cross-line empire, and developed technology to duplicate their natural ability. Using skudders and their human contractors, the Krith are trying to stabilize as many Timelines as possible so as to fight off a distant invasion.

Of course, all is not as it seems, and Mathers rebels against his employers about halfway through the first novel. He spends the remaining two either running from the Krith or just trying to survive.

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''The Timeliner Trilogy'' contains examples of:

* AfterTheEnd: Thousands of lines to the T-East, all destroyed by nuclear war - not even an atmosphere left.
* AlternateHistory: A near-infinite number thereof, all existing side-by-side, created by changes in the timeline.
* ForWantOfANail and InSpiteOfANail: While Timelines next to each other are mostly similar, massive changes occur over greater distances because of relatively minor changes long ago.
* GuardianOfTheMultiverse: The Krith... or so they claim...
** Also the Paratimers... or so they claim...
* LaResistance: The American Republican Army of ''At The Narrow Passage''
* MultiversalConqueror: In a way - the unknown, distant invaders attack at the same time in every Timeline, but they're not actually attacking ''across'' the timelines.
** The distant invaders aren't the only examples, though - [[spoiler:both the Timeliners and Paratimers are trying to build cross-line empires]]
* TimeTravel: Described as impossible, except for one scientific experiment which enabled the future to send messages back to the past - the only message ever received, in multiple timelines, was a warning about imminent destruction by an unnamed alien race.
* {{Utopia}}: The Cross-Line Civilization in the T-West - ten lines, all interconnected, a place of post-scarcity hedonism and industry, notable for see-through clothing and public sex parks.
** Sadly, it turns out to be [[spoiler:AllJustADream]]
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