The Once Upon a Time midseason finale, airing Sunday and titled "Queen of Hearts," won't just a battle between good and evil.

It will also pit mother against son in a struggle over curses, portals and faith.

With Hook and Cora, and Emma and Mary Margaret, all bearing down on Storybrooke during the episode, watch the following sneak peek to see Regina's plan for stopping all four of them - as well as Henry's passionate reaction.

Once Upon a Time Season 2 finishes up its 2012 run Sunday and then returns in January with new episodes.

Matt Richenthal is the Editor in Chief of TV Fanatic. Follow him on Twitter and on Google+.