Board Thread:Spoilers!/@comment-1894786-20151104191856/@comment-24674051-20151218160606

Agreed. There is no conclusive proof one way or the other on Blackbeard, though (discounting the AU) he should either still be in FTL, or perhaps Elsa had him executed. Interesting SIde thought is that, since Isaac wrote the AU and included Blackbeard, their paths would have had to cross at some point. There could be an interesting story in that meeting, though probably not one for the screen.

The marks, assumingthat is the rug in Gold's shop, are probably there for staging purposes, and it looks like it could be for a sword fight (between Hook and Blackbeard?). That would be my guess anyway.

As for Sidney, I read somewhere that his appearance will be as the Magic Mirror, meaning that it's likely to a flashback, and not the Underworld. Of course, we have not seen Sydney since Ingrid released him, so it is conceivable that he was a victim of the Spell of Shattered sight (even though it was mentioned elsewhere that no one died, but did they really check on everyone?).