Done Help with a sentence

[chizu]

hi,

I don't get the first (red) part of the sentence at all:

いつ終るともしれぬ混沌のなかで一人の若者が旅にでる。


thx

 

[Jazzu]

The entire sentence is something along the lines of "In the midst of [a period of?] chaos to which none can see an end, a single young man will embark upon a journey."

いつ and 終わる mean "when" and "to end" respectively.
*れぬ verb conjugations mean "unable to", similar to *られない, so しれぬ (知れぬ) would mean "unable to know/discern/see", and とも is used to link the two together with the impression of certainty.