Roxanne Dawson is incredible in this astonishing episode.
I don't really have anything to add that these other positive reviews haven't already stated, but I'm reminded of a quote from X-Files episode "The Blessing Way", said by Floyd Red Crow Westerman playing the character Albert Hosteen:
"There is an ancient saying that something lives only as long as the last person who remembers it.
"My people have come to trust memory over history.
"Memory, like fire, is radiant and immutable while history serves only those who seek to control it, those who douse the flame of memory in order to put out the dangerous fire of truth.
"Beware these men for they are dangerous themselves and unwise.
"Their false history is written in the blood of those who might remember and of those who seek the truth."