The numbering of the episodes for season 4 continues to be a source of utter confusion. This is due to the two-part episode (aired the same night) in December 2014. This isn't going to get sorted out until next season, so trying to fight it is pointless.
Anyway, by my reckoning, this is the official preview for Once Upon A Time episode 4x13, "Unforgiven."
"For the forces of evil to truly do damage, they must resurrect the evilest of them all. Now, only these heroes stand in their way."Hey, any time you can use 'evilest' in a sentence, you are way, way ahead of the game. And no, I would bet a huge sum of evilest that this episode has nothing to do with the Clint Eastwood film of the same name. But, tune in and find out.
A familiar face shows up this week.