Retro-Causality

The Shield Of Time, PART SIX, 18,244 B.C.

How does a divergent timeline affect events prior to the moment of divergence?

In 1137alpha, Emil Volstrup, futureward of the moment of divergence, begins to contact other time travelers on Earth at that time. Time Patrol bases in that year contact bases in earlier periods. Someone contacts Unattached Agent Komozino when she is in Eighteenth Dynasty Egypt, investigating the disappearance in that era of an expedition from her home millennium. Komozino takes charge of the emergency operation while seeking other Patrol agents of the same rank. A data scan suggests that Unattached Everard might be at the Patrol's Pleistocene lodge in 18,244 BC so Komozino goes in person to find him. Then she and Everard rally the others who happen to be at the lodge to become the vanguard:

"'...of the effort to salvage the future.'" (II, p. 300)

The lodge, sealed off for a limited period without overly affecting other events and with additional agents and equipment brought in as necessary, will be their temporary headquarters.

Does this sequence of communication and causation link Komozino and Everard to the post-divergence future such that, if they travel uptime, then they will definitely enter the altered timeline? We have to ask this question for the following reason. Everard:

"'...has repeatedly come to this lodge for rest and recreation, at various points of its existence, both downtime and uptime of the present moment.'" (II, p. 301)

Both downtime and uptime... 

After all of those - to him, previous - occasions, Everard had returned uptime to the twentieth century of the Danellian timeline, not of the alpha timeline. The one exception was when, "'Several years later than today, on the resort's calendar...," (II, p. 303) he had left the lodge aiming for New York, 1960, but instead had arrived in the equivalent year of the Carthaginian timeline. And, on that occasion, there had been no prior warning from anyone like Komozino.

Keith Denison leaves 1765 BC. Why does he arrive in 1980alpha instead of in 1980? Wanda Tamberly  leaves 18,244 BC. Why does she arrive in 1989alpha instead of in 1989? Wanda leaves the lodge just before Komozino arrives to alert Everard. When Everard has heard Komozino's story, he reflects:

"Wanda was bound for twentieth-century California. 'Now' she won't come out into anything of the kind." (I, p. 298)

How does he know that she will arrive in the alpha timeline, not in the Danellian timeline or indeed in some other altered timeline? What is the significance of the word, "Now...," in Everard's thought? Is he making the mistake of thinking of different times as if they were different places coexisting at the same time so that it would make sense for people in 18,244 BC to ask, "What is happening now in AD 1989?"

The word "now" would make sense in this context if Everard first acknowledged that alteration of timelines entails a temporal relationship between timelines and secondly had reason to believe that he is "now" in a later timeline.