Mr. Laser Beam wrote:
^ There is no Track C. In every episode we saw even prior to Y.E., Sela was still part of history, as was the battle in which the Ent-C was destroyed. Indeed, the alliance with the Klingons couldn't have existed without it, as it was the ship's destruction which spurred said alliance.
I don't know. The way I see it, the timeline existed in the following way:
Timeline A: Enterprise-C
destroyed defending Narendra III; Klingon-Federation peace treaty signed; USS Enterprise-D
commanded by Jean-Luc Picard; Tasha Yar dies on Vagra II; Sela does not exist in this timeline because her mother never traveled back in time to conceive her.
However, after the Enterprise-C
vanishes from its proper place in history, the following timeline (B) comes into play:
Timeline B: Enterprise-C
vanishes from Narendra III (presumed destroyed); Federation-Klingon relations deteriorate following incident; Federation-Klingon war begins following Romulan attack and lasts for two decades; Enterprise-D
commanded by Jean-Luc Picard and encounters Enterprise-C
when the latter travels into the future in 2366; Tasha Yar is alive but returns to the past with Enterprise-C
to defend Narendra III.
When the Enterprise-C
returns to her proper place and time, the second timeline above vanishes and is replaced by a third timeline (C). This timeline is similar to the first with the exception of there being two people named Tasha Yar prior to the death of the Tasha native to the original timeline on Vagra II as noted above. The Tasha from Timeline B conceives and gives birth to a half-Romulan daughter named Sela.