Once Upon a Time returns tonight with a trip to see a familiar good witch in the North. Check out our full preview below!

The question surrounding season 3 of Once Upon a Time is whether evil or wicked will win out in battle. Tonight’s season 3, episode 19 “A Curious Thing,” introduces a witch who is neither evil nor wicked. She is purely good. Glinda makes her first appearance tonight as Snow and Charming attempt to find out more about Zelena in the year that was.

Previously on ‘Once Upon a Time’

Belle makes progress figuring out Zelena’s plan to throw the laws of magic out the window and change the past. Regina summons the spirit of her mother, Cora, to learn why she gave up Zelena. They learn that in order to cover up a pregnancy that was the result of a one night stand, Cora nearly manages to get away with marrying King Leopold in time and convince him that the child was a product of their love. Snow’s mother Eva, however, overhears Cora admit her situation and rats her out to Leopold.

Regina and Snow managed to use this gift of hindsight clarity to mend their relationship and embark on a joint mission to stop Zelena from making their futures disappear.

This week on ‘Once Upon a Time’

Time is running out for Hook to use his magical lips on Emma and drain her powers. The clock timing the entire plot is snuggly resting inside Mary Margaret’s stomach. Although safe for now, Zelena recognizes that once the contractions start she must move into action. As long as Emma remains in her way, Zelena cannot succeed.

Check out the clip below to see which member of Emma’s family Zelena will target first.

Take a look at stills from this week’s episode and read the full synopsis in our photo preview post!

Watch Once Upon a Time season 3, episode 19 “A Curious Thing” tonight at 8 p.m. ET on ABC