Storybrooke is about to get Frozen.

In a new Once Upon a Time season-four teaser exclusive to The Hollywood Reporter, Frozen's Elsa (Georgina Haig) passes through the town's landmark hangouts (Mr. Gold's shop, Granny's diner), leaving her chilly mark wherever she goes.

Naturally, her unwelcome presence puts everyone — from Mr. Gold/Rumpelstiltskin (Robert Carlyle) and Mary Margaret/Snow (Ginnifer Goodwin) to David/Charming (Josh Dallas) and Captain Hook (Colin O'Donoghue) — on edge.

Though Elsa's face is never shown, her looming threat is powerful enough to get even Regina/Evil Queen (Lana Parrilla) to ready for the coming wrath. Just as the voiceover ominously hints at trouble for Storybrooke, Regina voices her dread, "Here we go again ....."

But Emma (Jennifer Morrison), in her signature red leather jacket, has her own thoughts on the new villainess: "Really?"

Frozen is getting a major presence on Once in the new season with a flurry of familiar characters as it picks up after the events of Disney's Oscar-winning movie: Anna (Elizabeth Lail), Kristoff (Scott Michael Foster), Prince Hans (Tyler Jacob Moore) and Pabbie the Troll King (John Rhys-Davies). Lost alumna Elizabeth Mitchell appears in a mysterious Frozen-related role.

Comic-Con attendees in July were treated to a special first look from the premiere that featured Elsa and Anna at their parents' grave site as they prepare for Anna's wedding to Kristoff.

Executive producer Adam Horowitz told The Hollywood Reporter in May that they were "honored" to incorporate the Frozen universe into Once. "We fell in love with [the movie] when it came out last year like everyone did, and we want to do our best to do it justice," he said.

Once Upon a Time returns Sunday, Sept. 28 on ABC.

Email: Philiana.Ng@THR.com

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