Read the official press release for next Sunday’s Once Upon a Time episode “Welcome to Storybrooke,” the first Storybrooke flashback!

ABC has released new information about the next episode of Once Upon a Time, which will show us what happened when the fairytale characters were first transported to Storybrooke. Read the complete press release below:

REGINA, OUT FOR REVENGE, VOWS TO KILL MARY MARGARET, AND DURING THE EARLY DAYS OF THE CURSE, A FATHER AND SON FIND THEIR WAY INTO A SUPPOSEDLY UNDETECTABLE STORYBROOKE, ON ABC’S “ONCE UPON A TIME”

Jamie Dornan Guest Stars as Sheriff Graham

“Welcome to Storybrooke” – Emma, David and Mr. Gold must protect Mary Margaret against Regina, who is out for revenge and has made it her mission to kill Mary; and Henry, fed up with all of the feuding, devises a plan to put an end to magic. Meanwhile, Regina discovers that a father and son have somehow found their way into her allegedly undetectable town as she and the fairytale characters deal with the effects of the newly cast curse 28 years prior, on “Once Upon a Time.”

Guest starring are Raphael Sbarge as Archie Hopper/Jiminy Cricket, Jamie Dornan as Sheriff Graham/Huntsman, Tony Amendola as Geppetto/Marco, Michael Raymond-James as Neal Cassidy, Beverley Elliott as Granny, Jarod Joseph Billy, Ethan Embry as Greg Mendell, Benjamin Stockham as Owen Flynn, John Pyper-Ferguson as Kurt Flynn and Steve Makaj as captain.

”Welcome to Storybrooke” was written by Ian Goldberg & Andrew Chambliss and directed by Dave Barrett.

We’ll bet anything that the father and son (presumably the characters named Owen and Kurt Flynn) who find their way into Storybrooke in the flashback are the mysterious hospital patient Greg Mendell and his dad!

Further, ABC has also announced that on March 31, an enhanced version of the season 2 episode “Queen of Hearts” will air. The episode will have pop-up facts and backstory details to let viewers in on some of the secrets of the show.

Once Upon a Time 2×17 “Welcome to Storybrooke” airs Sunday at 8/7c on ABC.