“Once Upon a Time” fans aren’t going to want to miss a minute of the two-hour Season 5 finale. ABC’s hit fairy-tale drama is setting up a powerful new storyline that will change everything in season 6.

Episode 21 concluded with Zelena (Rebecca Mader) discovering the truth about Hades (Greg Germann) and killing him with the Olympian Crystal. Unfortunately, the heroes were unable to celebrate his demise. The death of the ruler of the Underworld came with a price: Robin’s (Sean Maguire) life.

The episode concluded with an emotional funeral, but there was a bit of light. As a reward for helping defeat Hades, Zeus (David Hoflin) allowed Hook (Colin O’Donoghue) to return to Storybrooke. Emma (Jennifer Morrison) was ecstatic to reunite with her true love. However, it appears her happiness may set Regina (Lana Parrilla) down a dark path.

The former evil queen was finally able to find happiness this season, but it was torn from her when Robin sacrificed himself to save her. Now a promotional video for episodes 22 and 23 teases that Regina might return to her evil past as a way to grieve.

“You’re worried the Evil Queen is about to come out to play,” Regina says to Emma in the trailer for the finale. And based on Regina’s tone, it sounds like Emma and the rest of the Storybrooke folks have good reason to begin panicking.

“Deep down, the Evil Queen is who you are,” Gold (Robert Carlyle) tells Regina in another clip.

Could Regina possibly set up another curse to hurt the residents of Storybrooke? Will she team up with Gold, who is now in possession of a piece of the Olympian Crystal? Magic will definitely rock the small town in the finale, but it looks as though Henry (Jared Gilmore) has something up his sleeve to stop his adopted mom. He reveals that he “destroyed magic.”

Can the Storybrooke heroes survive without magic? Fans will have to watch to find out. The “Once Upon a Time” two-hour Season 5 finale will air on ABC Sunday, May 15, 7 p.m. EDT.