With the Season 3 finale quickly approaching, Once Upon a Time is heating up! Not only is there a baby on the way, but we’re getting a flashback to Oz as well. Season 3, Episode 20 (“Kansas”) is giving us both the birth of Snow White’s (Ginnifer Goodwin) baby and the introduction of Dorothy (Matreya Scarrwener).

Of course Zelena (Rebecca Mader) is doing everything in her power to get her grubby paws on Snow’s baby, taking down a hospital full of people to do so. But it seems her life in Oz wasn’t so easy. Once again we meet Glinda (Sunny Mabrey) — as well as the Witch of the North and of the East — who attempts to bring out the good in her friend.

But once Dorothy comes forward, fulfilling what happened in the classic tale (i.e. tossing water on the Wicked Witch and making her melt), our villainess might just be in trouble. We’re anxious to see what happens in this magical land!

Check out the synopsis for the May 4 episode:

“With Mary Margaret in labor and due to give birth at any moment, the residents of Storybrooke go on high alert in an attempt to ensure that Zelena doesn’t try to steal her newborn baby for use in her ultimate game plan to turn back time and change her destiny — while obliterating Regina’s existence. Meanwhile, in the land of Oz of the past, Glinda tries to convince Zelena to fight her evil tendencies and join her and her sister witches as a protector of Oz. But the appearance of a young girl from Kansas could turn out to be her undoing.”

What do you think about the description for this episode? Hit the comments and sound off!

Once Upon a Time airs Sunday nights at 8 p.m. ET on ABC.

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