He's exhausted. The days all blur together, a twisted jumble of scribbled pages, whispered summons, darkened eyes and bellowing screams. His mother is exhausted, running herself ragged and raw trying desperately to pull her friend back from the darkness; eyes bloodshot and fingers bleeding from reading spell after spell, concocting potion after useless potion, driving herself to insanity in her desperation to reclaim her from the darkness.
He can't lose both his mothers. He won't. This needs to end, today.
Gripping the dagger with shaking hands he calls into the wind, "Emma Swan. Mom, I summon thee."
She appears in a swirl of acrid smoke, twitching and snarling like a crazed animal, eyes wide and pleading.
"Henry, please," she begs, voice hitching and cracking, the pitch too high, the cadence all wrong. She's not his mother anymore, she ceased to be the woman he loves when that thing corrupted her. What little is left of her lingers there behind her eyes, trapped, begging, and he's tired of fighting back.
A small smile tugs at his lips, a final goodbye painted across his face as he gazes at the remnants of his birth mother; the woman he desperately longed for when he thought his mother wasn't enough, the woman he grew to know and love, the woman who knit his family back together, who mended the bonds and made them whole again.
"I surrender," a simple statement, offered like a pardon as he embraces his mother one last time, sliding the dagger into her back, breathing in her last breath as the world fizzles and burns, her screams dissolving into a final whispered caress of "I love you" pressed against his ear as she fades in his arms and his vision dims to black.