While Jekyll and Hyde started out the episode tied together in the same body, Dr. Jekyll created a serum to separate the good and the bad in a person, allowing he and Hyde to roam free of each other.
That serum also came in handy (or so she thought) for Regina, who spent the episode wrestling with the possibility that her former, evil self could come back out at any time. So, the plan was for Regina to be injected with the serum, and then as soon as the Evil Queen emerged, she would kill her.
That’s what Regina thought she did, but there was no way the Evil Queen was staying a pile of ashes. By the end of the finale, she was back and ready for revenge.
Unfortunately, that’s exactly when Hyde showed up to announce that he now owns the place. Dun dun dun!
Once Upon a Time returns to ABC in the fall.