While I loved all previous episodes for their ingenuity and humor, this one fell short for me, since it was the least intelligent one. It was possibly built around Farady's "skin"- sentence, which reflects the actual north-American situation, but not history of mankind over the millenia. It is power and ownership that mankind is obsessed about, not skin.
From a storytelling point of view this episode was just a stalling filler before the series finale, and it was not thought-through very well, like the previous episodes, which were. The situation that takes most of the time here is just a (boring) standard setting that has been repeated too often in the past, and could have been avoided easily. Hence only six stars from me.
From a point where one embraces actors' performances, it was clearly a 9 or even 10. If I would say, it's even a bit tiring here how good Mr. Ejiofor is in every aspect, and also Mr. Simpson, would you believe me ? But it is. A tiny bit. Not that I complain.