TBH, I thought there were two possibilities - one of which was the Doctor gives the Cyberman what it wants and then spends an episode (or more) trying to correct the mistake - or it all becomes a kind of race against time with both the Tardis Team and the Lone Cybermen trying to reach the magic Unobtanium first - with possibly some added complications from the Tardis Team not knowing precisely what it was.

But I was pretty certain from the moment the Lone Cyberman turned up here that we were in "Doctor gives it what it wants" territory.