The behind-the-scenes stills released for the upcoming Once Upon a Time episode “The Doctor” reveal more of Regina’s past encounters with Jefferson and Rumpelstiltskin.

Following the release of the promotional stills for “The Doctor,” which is the episode which airs following this Sunday’s “The Crocodile,” we’ve now got a set of behind-the-scenes images that reveal even more about the episode:

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In this episode, not only do we seem set up to finally learn the identity of David Anders’ mysterious Doctor Whale, but we’ll also get another chapter of Regina’s backstory! From these stills it would appear that the story will follow on closely from what we learned in “We Are Both,” where Regina accepted to become Rumpelstiltskin’s apprentice.

The official description of “The Doctor” reads:

As Regina tries to refrain from using her magic in order to regain Henry’s trust, she starts seeing a ghost from her past; Mary Margaret and Emma find a survivor from an Ogre massacre; Regina struggles to learn the dark arts.

We can gauge from the images released that the survivor who Emma and Mary Margaret find is Hook, who is apparently going by a different name, for whatever nefarious purpose.

As for Regina’s ghost, we have no idea! But it’s interesting that she’ll encounter Jefferson – and if not teaming up with him, at least not actively working against him. Wonder what kind of past the pair actually shares!

We’re also glad to see that Once Upon a Time evidently got Sebastian Stan for more than the three episodes he was originally scheduled for. While we’ve only seen him in fairytale land, hopefully his happy ending with Grace at the end of “Lady of the Lake” won’t be the last we’ll see of him.

Once Upon a Time returns Sunday with the fourth episode of season 2, “The Crocodile,” which introduces Captain Hook!