Once Upon a Time bosses on rise of new big bad 

Warning: This story contains major spoilers from the fall finale of

not only dropped a shocking reveal when it comes to who cast the curse but also introduced an even greater foe in its fall finale.

Via flashback, viewers learned that Drizella (Adelaide Kane) abducted Henry (Andrew J. West), poisoning his heart in order to force Regina (Lana Parrilla) to help her cast the curse. Hence, if the curse is broken, Henry will die. Alas, if the curse is

broken, Lucy (Alison Fernandez) will die, putting Regina in the difficult position of deciding whether to sacrifice her son to save her granddaughter.

“As Drizella promised, she’s come up with what she believes is a foolproof plan, so there’s a conundrum,” executive producer Edward Kitsis tells EW. “Regina is going to be looking for the help of Zelena and whoever she can to find the third way that doesn’t kill Lucy or Henry, and that breaks the curse.”

But the threat runs deeper than that as Drizella was not acting alone. The curse wasn’t actually cast by one particular witch, but the Coven of 8 — a group of mysterious origin whom Mother Gothel (Emma Booth) is trying to reunite in Hyperion Heights. “We understand that there is a Coven and she’s gathering them for a purpose that will be revealed in the second half of the season,” Kitsis says of the new threat coming in 2018. “The witches are all in Hyperion Heights, so we’ll be meeting them in the second half of the season.”

For now, the Coven’s true motives are somewhat shrouded in mystery. “The Coven is going to be different [from the villains we’ve seen before] because it’s led by Mother Gothel,” Kitsis says. “What she wants is going to directly affect one of our characters and yet the audience doesn’t know which one yet. They would assume it is based on what they’ve seen, because we’ve seen her be locked up, but as Lady Tremaine warned us, ‘Don’t let her out,’ she is out and we’re going to be realizing they’re gunning after one of our characters for a very specific reason.”

bosses are coy to reveal any of the Coven member’s identities, only teasing there will be a pretty major new face among them. “I think there’s going to be some surprises,” Kitsis says. “What happens with the witch story line hopefully will also be surprising. We will be seeing someone in episode 11, which is a reference we’ve never done before, which is from the Haunted Mansion.” (Crossing fingers for Madame Leota!)

One character who’s definitely not part of the Coven is Drizella, whom Mother Gothel had been manipulating for the express purpose of transferring her magic to Anastasia. “Drizella was warned not to let Gothel out, and she did and now she finds herself in a pit with her mother, who she hates, so their family has only grown more dysfunctional,” Kitsis says. “Drizella’s desire for revenge only grows stronger. We’ve seen moments of kindness from Drizella, so we’ll have to see whether or not she is fully an Evil Stepsister, or if she can be redeemed, but right now, she’s out for revenge.”