"Once Upon A Time" Season 3, Episode 13, titled "Witch Hunt" airs on ABC this Sunday, Mar. 16. This new episode tackles the backstory of the Wicked Witch of the West (Rebecca Mader). The Evil Queen (Lana Parrilla), Emma Swan (Jennifer Morrison) and Snow White (Ginnifer Goodwin) team up again to fight yet another common enemy.

Spoiler alert: This feature contains spoilers on Once Upon A Time Season 3, Episode 13. Read at your own risk.

In Once Upon A Time Season 3, Episode 12 ("New York City Serenade"), viewers learned that there is a new curse that brought everyone back to Storybrooke. There is a missing one year memory that Emma Swan has to put together.

The flying monkeys from Oz are wreaking havoc in everyone's lives. One of them (Christopher Gorham) even flew to New York to make sure that the saviour, Emma Swan, stays out of the way. Thanks to Captain Hook (Colin O'Donaghue), Emma Swan has recovered her memory. The saviour learns mum Snow White and dad Prince Charming (Josh Dallas) are pregnant. But it's the least of her concerns. She has to break another curse.

The Wicked Witch, Zelena, sends a flying monkey to get a bit of the Evil Queen's blood. Regina has no idea who the enemy is at this point. In Once Upon A Time Season 3, Episode 13, she will team up with Robin Hood (Sean Maguire) to get to the bottom of the stolen castle.

One of the best moments of "New York City Serenade" transpires when Snow White comforts Regina and convinces her to keep her heart, even if it means tremendous pain. Regina misses Henry (Jared S. Gilmore), but the two might see each other again in OUAT 3x13.

Snow White and the Evil Queen seem to have worked out their differences. Captain Hook jokes it is boring that way. But boredom has no room in a world where the Wicked Witch is out to destroy the Evil Queen and everyone else. Once Upon A Time Season 3, Episode 13 is all about the Wicked Witch, and perhaps a bit on Rumplestiltskin (Robert Carlyle), too.

Belle (Emilie de Ravin) seems convinced Rumple will come back from the dead soon enough. The Dark One could not have died in the first place. Belle hints to Neal (Michael Raymond-James) that they should go looking for the dark wizard's dagger. But this happens before everyone is cursed by the mean green witch.

Oncers can expect a new episode that will only spark more questions than answers. It has been OUAT's style to spread the movements thinly in most episodes. OUAT Season 3, Episode 12 answered a few questions on the mid-season finale and opened the door to even bigger questions.

It is still a mystery how Princess Aurora (Sarah Bolger) and Prince Phillip (Julian Morris) learned about the curse at Snow White's and Regina's castle.

One Upon A Time Season 3 is just about to get even better with the Wicked Witch around. Episode 13 will reveal more of what happened since Snow White and everyone else returned to the Enchanted Forest.

Watch: Once Upon A Time Season 3, Episode 13 promo video (ABC on YouTube)

One Upon A Time Season 3, Episode 13 takes place in Storybrooke and the Enchanted Forest. Episode 14, titled "The Tower," tells the OUAT story of Rapunzel.

More TV Guide and Spoiler Features

'Once Upon a Time' Season 3 Spoilers: 'Wicked Witch' in Storybrooke, Emma Swan in New York, and the Evil Queen's Evolution! [Watch Promo Videos]
'Once Upon A Time' Spoilers: Creators Want to Feature 'Frozen' and 'Brave' Characters in the Series' Future Episodes, Who Should Portray Anna, Elsa and Merida? [READ]