Headcanon about what might be happening on Sunday with Killian and Emma and Zelena where he's clutching his chest. (based on CTV promo and filming spoilers)

"What the hell is happening?"

Uncertainty begins to crack her façade as she watches him clutch his chest, a reaction she wasn't quite expecting from Zelena's tethering spell, the obvious pain on his face making her begin to worry that placing her trust in the green one might have been misguided. One look at the witch answers that quickly, as for once, she's been stunned into silence.

Killian falls to his knees, the agony on his face all it takes to finally break her as she moves to the floor to cup his head between her palms.

"Killian…I'm sorry, I don't know what's happening."

As he lifts his head and their eyes lock, Emma feels the first tug, a pull deep inside as if some magical force is clutching at her soul. She tries to pull away but his hand grabs at her wrist, her pale skin bruising under the force of his fingertips as he struggles to keep her by his side.

She feels the moment it happens. The tug turns into a rip, her mouth falling open in a silent scream as both pain and a sense of lightening occurs almost simultaneously.

He collapses, finally releasing her wrist as he crumples in a heap by her knees, the frantic rise and fall of his back as he breathes the only signal that she hasn't lost him, not completely. She reaches for him and almost recoils when she feels the change in the fabric beneath her fingertips, his leather gone and replaced with something else, something stiff and abrasive. His head lifts and her hand does fall in shock at what she sees, or rather, what she doesn't. Midnight has replaced day. Darkness has shrouded the light in his eyes.

"Emma?"

"Well isn't this just lovely. Two Dark One's for the price of one."

The air snaps at the force of Emma's turn towards Zelena, the wicked glee on the witch's face as she looks down at them setting Emma's blood to a near boil.

"What did you do?"

"Me, oh, this wasn't me, dear, this was all you. I should have seen this coming, but, considering I was really only concerned with myself, I didn't give the two of you that much thought. Don't you see, Emma, Excalibur is whole. The pointy little tip of that sword is the dagger of the Dark One and you, well, you just had me tether your True Love to it. Your mother and father may share a heart, but you and your pirate, you get to share the darkness."

"Bloody hell."

Her attention is drawn back to Killian and they simply stare at one another, so many things being said without words spoken, the entirety of all that has happened sparking between them like a live wire. Neither notice, nor care, that Zelena has disappeared, the green smoke signaling her departure dissipating in the thick air around them the only evidence she had been there at all.

His hand covers hers on the cold floor and she finally breaks, hot tears softening the sharpness of her cheekbones as she cries for what she has done, both to him now and everything before. She barely registers her body being tugged up until she finds herself standing, blessed warmth finally seeping into her bones as he wraps her tight in his embrace.

She doesn't know what this will mean, if this will change anything she must do, but in this moment she doesn't care. She's not alone anymore. When he pulls her head gently from his chest to slant his mouth over hers, she lets him, allows herself the comfort of the love pouring from his lips with a hunger matched only by her own.

She can't help but begin to believe that they can figure this out together, that somehow they can save everyone and themselves.

The Dark One lies. The Dark One tricks. What she doesn't see is that it can also trick itself.