https://en.wikipedia.org/wiki/Fringe_(TV_series)#Parallel_universe
Fringe using the Alternate_Universe as part of the overall story was fascinating.
https://en.wikipedia.org/wiki/Mythology_of_Fringe#The_parallel_universe
https://fringe.fandom.com/wiki/Fringe
https://screenrant.com/fringe-season-6-canceled-reason-why
https://www.looper.com/318767/heres-how-you-can-watch-every-season-of-fringe