In Once Upon a Time season 4, episode 2, we flash back to David’s time as a shepherd, and learn that he knows someone from the Frozen universe!

This Sunday, the second episode of Once Upon a Time season 4 will feature David (Josh Dallas) flashbacks, complete with dodgy wig and shepherd’s rags.

The “White Out” promotional stills reveal that he used to know – dun dun dunnn! – Anna (Elizabeth Lail), Elsa (Georgina Haig)’s sister!

But how?! Did Anna encounter him after leaving Arendelle? Notice the sword she’s holding – where did she get it?

The official synopsis released by ABC reads:

“In the Enchanted Forest of the past, Anna tries to teach a meek David to fight Bo Peep, a brutal warlord who is threatening to take his and his mother’s farm away if they don’t pay her price.”

That sounds amazing! Meanwhile in Storybrooke,

“Elsa is startled by Emma and accidentally traps them both inside an ice cave, with the frozen temperature placing Emma’s life in peril.”

It seems like this will be the beginning of the beautiful friendship Jennifer Morrison has teased will form between the two strong women.

And finally, we learn what Regina (Lana Parrilla) and Mary Margaret (Ginnifer Goodwin) will be up to this week:

“Regina, depressed over her likely breakup with Robin Hood, secludes herself away from the town and Henry, which saddens her son. And with the townspeople considering Mary Margaret their leader, she faces her first leadership task in trying to re-start a generator and restore the town’s electricity after Elsa freezes and damages the power lines.”

We’re looking forward to seeing Mary Margaret step more into a leadership role this season. Especially with David entangled in the Frozen arc, she’ll need something to do (you know, aside from taking care on an infant!).

Once Upon a Time season 4, episode 2 “White Out” airs Sunday at 8/7c on ABC.

Gabrielle Rose returns as David’s mother, while Sons on Anarchy‘s Robin Weigert guest stars as Bo Peep.