'Once Upon A Time' is back with season 4 episode 15 this Sunday evening and for sure fans of the hit fairy tale-inspired series will be delighted to know that Regina will do everything and anything to help our good characters, even if it meant pretending to be one of the bad guys yet again. Spoilers revealed that she may be befriending Maleficent to carry out a magnificent plan. Don't miss the brand new episode this week. Tune in on ABC at 8 p.m. EST or simply watch 'Once Upon A Time' season 4 episode 15 online using free online stream link below.

Note: This feature contains spoilers on the upcoming episode of 'Once Upon A Time' Season 4. Kindly read at your own risk.

Previously on OUAT, Maleficent's secrets were unraveled, to the surprise of Snow and Charming. Amid the many revelations, Mary Margaret confesses to Regina that she and David may be the reason why villainous Maleficent does not have a child. Elsewhere, Emma realizes that something was being kept secret from her while Henry and Regina aspired for Pinocchio to learn the truth. This week, Regina must prove to the Queens of Darkness that she still has that evil side of her by getting her hands dirty. Will she do a terrific job in proving herself just so she could play spay for the good characters? Find out by tuning in on ABC at 8 p.m. EST. Watch 'Once Upon A Time' season 4 episode 15 stream through the free online stream link at the bottom.

Interestingly, show executive producer Edward Kitsis dished that Regina may be putting her life at stake in her undercover mission against the Queens of Darkness. But ABC's official synopsis already confirmed that Regina's efforts will not go in vain since she will be earning Maleficent's trust above everything else. Kitsis also admitted that Pinocchio's storyline will also be a big part of the upcoming episode. "We are going to dive more into the backstory with what happened with him writing pages in the book and why he was doing what he was doing," he said. Watch 'Once Upon A Time' season 4 episode 15 stream using the free online stream link at the end of this post.

Actress Kristin Bauer, who plays Maleficent in the show, recently spoke to TV Fanatic and gushed about her character. "She's definitely fueled by revenge and pain at the beginning, and we find out more about that through the season. Revenge is often a common motivator for heroes and villains. You know, we see Superman, Spiderman, Batman, blah, blah, blah...revenge is very clear motivator for Maleficent at the beginning," she said.

The official synopsis of 'Once Upon A Time' season 4 episode 15 reads: "In order to infiltrate the Queens of Darkness as a spy for the heroes, Regina must prove she's still willing to get her hands dirty. Meanwhile, Emma, David and Mary Margaret scramble to keep tabs on their undercover operative. Hook requests an unusual favor from Belle as Henry makes progress on his search for the Author. In a Fairy Tale Land flashback, Regina befriends Maleficent and helps her to rekindle her lost spark."

"Enter the Dragon" is set to air this Sunday evening on ABC at 8 p.m. EST. Watch 'Once Upon A Time' season 4 episode 15 stream using the free online stream link here.