Once Upon A Time's Emma Swan (Jennifer Morrison) continues falling farther down the rabbit hole of evil now that she's the Dark One. And that means betraying those people she loves most.

Last night's episode saw Emma betraying her own son, Henry (Jared Gilmore), by taking out the heart of the girl he's fallen for. Ouch.

It seems that Dark One Emma will go to any lengths to get what she wants: last night, her goal was to free Merlin (Elliot Knight), but she still needs Excalibur pulled from its stone. However, Mr. Gold (Robert Carlyle) doesn't want to become the hero Emma needs to do that.

A preview of next week's episode, "The Bear and the Bow," shows that Emma will go after those who Mr. Gold loves—particularly Belle (Emilie de Ravin)—and play on the man's greatest fear to coerce him into becoming brave, something even Merida (Amy Manson) could not achieve.

In the clip, Mr. Gold faces off against a bear to save Belle from whatever fate Emma has in store for her. Of course, this is a ploy to turn Mr. Gold into a hero so that Dark Emma gets what she wants: someone who can pull the sword out of the stone.

Emma needs the sword extricated from the stone so that she can reunite it with the Dark One's dagger (which is actually the tip of Excalibur) and kill all the light in the world.

However, there is a good reason behind Emma finally and completely embracing her dark side, at least according to an interview with Morrison by PopSugar.

"They do establish with all of the Dark Ones in the past, which they kind of go back through in the beginning of the season this year, that everyone takes the Darkness for a good reason," said Morrison. "Rumpel takes it because he wants to be braver for his son. Emma takes it because she's saving the whole town from being destroyed by the Darkness."

This is likely a flashback we haven't yet seen: something that happens in Camelot that finally sets Emma upon her dark path.

However, things are going to grow even darker for Once Upon A Time later this season. TVLine reports that the show recently announced casting for a character only known as the "Distinguished Gentleman." That, plus the fact that co-executive producer Eddy Kitsis referred to the second half of the season as "hell," means that it is likely that the Storybrooke gang might have to traverse the Underworld and come face to face with Hades himself.

Once Upon A Time airs Sundays on ABC.

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