Emma (Jennifer Morrison) is heading down a dark path on ABC's Once Upon a Time and one of the show's creators warns that fans should be concerned.

The Author Sticking With Gold As Emma Turns Dark on 'Once Upon a Time'?

After Emma killed Cruella (Victoria Smurfit) in the latest episode of Once Upon a Time, it has been made clear that she is really flirting with the dark side. Of course, this is good news for Mr. Gold (Robert Carlyle) but bad news for pretty much everyone else.

Once Upon a Time co-creator Adam Horowitz spoke with TVLine about this dark development this week.

Regina 'Joins Forces' With Emma For The Greater Good on 'Once Upon a Time'?

"The audience should be very, very concerned that Emma has irrevocably headed down a path," said Horowitz, suggesting that this path was a very dark one.

"If you thought Emma was in danger of going dark from learning what her parents did [to Maleficent"s daughter Lily], now we have to deal with the danger based on her own actions," Horowitz added, saying: "Emma crossed a line."

With only four episodes left of the season, the focus will now shift to what Emma chooses to do and how evil she may become.

"The final four hours of the season [including the two-hour finale airing May 10] force us to grapple with the action Emma takes," Horowitz teased.

It also remains to be seen what sort of repercussions will occur for Emma in the wake of Cruella's death.

Once Upon a Time airs Sundays at 8 p.m. ET/PT on ABC.

Watch the promo for the next episode of Once Upon a Time here:

Tags: Once Upon A Time television ABC