Board Thread:Show-Related Questions and Answers/@comment-26569765-20171118234222/@comment-5106672-20171119032256

Option A does not make a whole lot of ontological sense, unless we dig into a deep quantum hole of infinite diverging universes created by different key choices / events playing out differently / the such. Like, for instance, a parallel universe where Cora kept Zelena which unfolded in a totally different way, or one where David went on to marry Abigail, and so on. This would be a universe diverging when Snow and David found a way to strip Regina of her magic and yada yada.

That could be, except Once was a multiverse to begin with, with each world being completely different (the EF, the LWM, Wonderland, Oz and so on), and from a narrative standpoint merging the two does not make a lot of sense.

So I'm goint with option C – that's a gaping plothole that we really need to overlook to keep enjoying the show. I'm fine with that.