"I know what he's going to do next" is followed through into TST.
From Ariane de Vere:
"He’s planned something; something long-term; something that would take effect if he never made it off that rooftop alive. Posthumous revenge. No – better than that. Posthumous game."
That's what sets of Moriarty on the wrong track in TST - he's waiting for the sign that the game has started, and then tries to connect it to Moriarty (the Borgia pearl - I actually wondered if Mycroft was deliberately leading him astray on that, but I've changed my mind now). Then we find out in TFP, that Sherlock was right - there was a posthumous game - but it was Eurus, rather than Moriarty, who was behind it.
So yes, this is an idea that follows through from TAB. It's just not what we (or Sherlock) expected.
I do agree that TAB was mainly about the opportunity to do a Victorian one-off, though.
Last edited by Liberty (February 17, 2017 7:23 pm)