Is that Alchemy circle thing filling up with water? Like a well of wonders. Or is it wraiths coming out of there? Looks pretty ominous, whatever it is.
Looks black to me, and the way Rumple’s moving makes it look like maybe he’s rising up out of it, so I guess the dark stuff is the Dark One returning? And given that Rumple said to Zelena that she shouldn’t have brought him back, I’m wondering if that oozy dark stuff is her doing, not BelleFire’s, they just happen to get to the place just in time to see what she’s doing. Neal might try to stop her, and that’s when she takes his heart (if that is indeed what she’s done) to get him to back off so she can take Rumple away.