"Once Upon a Time" just gave a big reveal in last Sunday's episode. Belle (Emilie de Ravin) was found to be pregnant with Rumple's (Robert Carlyle) child. How this will specifically affect the story and the characters remains to be seen, but show executive producer Edward Kitsis gave some hints on what to expect after this big reveal.

In a recent interview by Entertainment Weekly, Kitsis shared that Belle's pregnancy will bring a huge impact to the show.

"It's going to affect both of them," Kitsis said. "When he finds out that she's pregnant, it's going to affect him, it's going to affect her, it's definitely going to affect his motivation," he added.

Belle's pregnancy may be happy news but not quite for Rumple, who had promised his second-born to a healer. This deal is now Hades' (Greg Germann) deal, which means that Rumple is under the control of the god of the Underworld.

Meanwhile, the next episode of "Once Upon a Time" will give focus on the brothers Killian (Colin O'Donoghue) and Liam (Bernard Curry) Jones, as Killian a.k.a. Hook tries to escape the Underworld.

"Once Upon a Time" never fails to deliver dark storylines as Storybrooke characters find themselves trapped in Hades' realm. But the show is bound to get even darker as a new arc has been announced – the mental hospital arc.

Two new actors have already signed up to be part of the twisted fairytale series; they will first appear in the mental hospital arc. "Being Human's" Sam Witwer and "The Man in the High Castle's" Hank Harris are on board to play the role of Jacob and Nathaniel, respectively.

Jacob is described as the mental hospital's brutal and evil warden who enjoys tormenting his patients. Nathaniel is one of them and is one of Jacob's favorite subjects. Fans will just have to wait for this new arc in the coming weeks to see how these two mental hospital characters will fit in the fairytale world.

Catch "Once Upon a Time" season 5 every Sunday, 8 p.m. ET on ABC.