On Once Upon a Time Season 3, Episode 16 ("It's Not Easy Being Green"), we'll finally get to see Regina and Zelena face off in the present of the show, and based on this sneak peek of the episode, the showdown is going to be exactly what we've been waiting for.

This clip opens with Emma, the Charmings, and Tink pushing through a crowd of townsfolk milling around. They're wondering where Regina is, and Tink is worried that if Regina doesn't show, the Wicked Witch will take it out on the rest of them. Clearly, a threat has already been made, and the town is turning out to see what happens next.

Tink has a reason to be worried. Zelena appears, and threatens to "let the Dark One off his leash" if Regina doesn't get there in five minutes. (Rumple's face when he hears that threat is heartbreaking. Clearly, he hates being Zelena's puppet.)

Fortunately, Regina does get there in time, and sparks fly immediately.

"Didn't anyone tell you? Black is my color," Regina begins, but things quickly get more serious from there. Apparently Zelena has told Regina they are sisters again, and while Regina has accepted that fact, she's still confused about what she ever did to Zelena.

"Isn't it obvious?" Zelena replies. "You were born."

Regina's response to that is sheer awesome. Check it out for yourself below!

Catch this episode of Once Upon a Time on Sunday, April at 8 p.m. ET/PT on ABC.