Would it not be a fantastic twist to discover that Jim Moriarty's call by the pool in TGG was from Eurus? Been discussed, of course, and there seems to be some small consensus that the call was from Irene Adler. But - has that been thoroughly thought through?  What was motivation for Moriarty to come back in and threaten Sherlock by the pool other than some great discovery about him?  

Newbie here. If this has already been thoroughly sussed out, your pardon.  I have never really liked the notion of Adler turning to Moriarty for help.  She was not evil.  She was a business lady on the fringe of acceptable society who was trying to protect herself. Yeah, she used methods that were questionable.  So does Sherlock, more than once.