Written by Gordon Michael Woolvett.
And part of the season ending story arc.
I haven't seen the episode yet, but I've heard that the opening quote is by someone who appears to be human, but is given as the year 1116 CY. This is the equivalent of approximately 3609 BC. This is around the time of the Akkadians and Sumerians with their lingual developments, so this may be a little too early for this quote.