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Dallas explained, "Wait until you see this week's episode!...Elsa is startled by Emma and encapsulates them in this ice cave where Emma's life is in great, great danger. David comes to their aid and sort of talks Elsa off the ledge."

No surprise really, but "Let It Go" is playing a lot in Dallas' head these days. "It's constantly playing," he said. "Who knows, but maybe I've sung it myself a little bit. I might just hum it a little bit every now and then. But I also love the version that's out there [he begins to sing], 'f--k it all, f--k it all.' That's pretty good."

Ginnifer Goodwin, who plays Mary Margaret/Snow White, recently told E! News about the Frozen ladies coming to OUAT. "We are portraying them in our Once Upon a Time way. We're not duplicating anything about the animated feature. Our versions of the characters were inspired by the feature. But at the same time there is something undeniable about these actors and how much they resemble them in spirit and in appearance."

With the town frozen over, Mary Margaret is being pulled in all different directions. "She is back as mayor and has a lot of stuff to deal with as well as breastfeeding and changing diapers with Neil," Dallas said. "But she's Snow White, baby! She can do it all."