Re: Hybrid is mentioned a lot in the last episodes
A passing reference in the first episode of this series was all I turned up after a quick google. It was a bit like being expected to care about the kid with the tattoo, last week.
Confession: I nodded off twice during Heaven Sent. Aside from The Doctor having been replaced by a clone (I assume they'll come back to that?), this episode was a waste of time. I liked the matrix, though - still waiting for the Valeyard to reappear (unless you meant the Wachoski film, which is a couple of exciting set pieces, broken up by a load of boring waffle).
@h4rm0ny Fair point about not regenerating. Still, The Doctor is dead and is survived by his umpteenth clone.