Emma Swan (Jennifer Morrison) and Regina Mills (Lana Parrilla) have come so far during the first three seasons of Once Upon a Time. What once started out as a bitter rivalry over the love and adoration of Henry Mills (Jared Gilmore), it seems as though these two fierce mamas have reached a level of cooperation and, gasp, friendship — that is, until the Season 3 finale.

In one fell swoop, Emma returned to present day Storybrooke with the one person who could ruin Regina’s shot at happiness with Robin Hood (Sean Maguire): his wife, Marian (Christie Laing), who should have died back in the Enchanted Forest. Will this hiccup in Robin and Regina’s love life be enough to turn Regina and Emma back into enemies? You betcha!

Jennifer tells TVLine that while it was “cool and interesting” to explore “this idea of these adversaries finding common ground to save Henry,” that will most likely change heading into Season 4.

“It makes sense that we’re going back to a place where these two women are going to be adversaries,” Jennifer told the site. “Emma definitely wants Regina to be with Robin, and she never would have intentionally done anything to hurt that. But she’d also never let someone die in the circumstance that [Marian] was in. So it’s one of those situations where doing the right thing is going to have terrible repercussions. But I think it’s good for the show. We should have conflict between Regina and Emma, because that’s where the show got its feet in the first place.”

We totally get where Jennifer is coming from when she defends Emma’s heroic actions, but it’s sad to see these two characters take one step forward and two steps back. Yes, it was awesome to see these ladies trade blows in the first few seasons, but we kind of loved them as magical allies. Hopefully they can work through this!

Are you glad Emma and Regina will have it out for each other again? Hit the comments and sound off!

Carson Blackwelder is an Assistant Editor at Wetpaint Entertainment. Follow him on Twitter and Google+!