"I'm sorry Sylvia," Steve had admitted softly. "They need you," Hill had said, reaching for the collar. But she had pleaded with them, "Promise me you'll get the collar back on before I turn on someone…Promise me!" And over their protests, "Promise me you'll kill me if you can't."
Now Sylvia was lost in the current. She was drowning. She didn't even register her normal fear of heights as she plummeted to the ground. Power made her limbs heavy, as she struggled to keep her head above the current. But, she sunk deep down into her own consciousness. The current stilled, the surface became like a glass window at an aquarium. She banged on the glass to no avail now a prisoner in her mind, only able to watch as the remnants of the tesseracts power took control of her body. She wondered, was this how Loki felt? Was he also a prisoner of his own mind? She only hoped a machine would draw her ire first.
Time seemed to stand still for Steve as the Avengers watched her fall from the sky. About to call for Thor or Iron Man to catch her from her free fall, he saw Sylvia right herself in the air and land crouched on one knee. Resolving to keep an eye on her he released the breath he hadn't realized he'd been holding and proceeded to fight his way over, comforted when Thor declared he was near.
Her body whirled, and with a sickening glee she could barely sense, ripped the innards from another of Ultron's Legion. The tesseract had given her some sort of telekinesis. With the collar on to prevent her from accessing the power, only great concentration allowed her to nudge chess pieces. Unleashed, she tore hearts out, crushed beings with concentrated blasts of her presence, and laughed. Yet the glass remained solid, and only the sickening feeling of the current reached her and the vision of her destruction currently constrained to machines was all she could see. "Just the machines," she pleaded with herself as murky laughs resonated in the waters.
It was nearly over, Steve ordered the Avengers converge on Sylvia's location. "We'll have to get close to her to snap the collar back on," Barton declared handing the retrieved collar to Steve. "We'll need her distracted," Natasha supplied. Their eyes pierced Steve's and he couldn't match them, he turned away to see that Sylvia was advancing on Thor, who was also looking at Steve. Realizing they needed to act quickly now to save her from herself, Steve and the others quickly leapt into action.
Each attempted to get close enough to restrain her (Steve and Stark), close enough to knock her out (Thor, Natasha, and Barton), and close enough to land a hit (the Hulk). But Steve didn't want to hurt her, and he lamented his apparent uselessness as he brought his shield up to defend the non-physical blast that had him flying back in midair. "You cannot pull your punches, Captain Rogers," came Thor's deep voice as he caught him and brought him to a less haphazard landing. He continued gently, "We do her and ourselves more harm by allowing her to remain in this state." Clapping him on the back Thor rejoined the fray. The hammer seemed unaffected by her magic as she was forced to dodge his blows and throws. An idea sprung to Steve's mind and he quickly relayed the strategy to the others. Hawkeye's barrage was deflected, Natasha thrown back for attempting to get too close. "We're going to have to kill her," she argued while pulling out her pistols, disheartened when Ironman's blasts fizzled into nothing. Thor got close enough to swing. Her dodge brought her into Steve's reach. Steve warred with himself, he could never hit her. Time lengthened as he swung his shield at her, she deflect it and sent it tearing off of his arm and back behind her. Steve met her eyes and something he saw, some hesitation, made his left hand clamp down on her shoulder of its own accord and crush her to him, his right going for the collar on his belt.
Sylvia watched from within the glass as the Avenger's tried to take her out. Tears pricking the corners of her eyes as she watched each get weary and sustained more injuries at her hands. Steve went flying back behind his shield and she cried out against the glass slamming her fists against it in her pain. Steve again swam into her vision, she met his eyes and could barely feel his hand on her shoulder as he crushed her to him and kissed her. Her ears roared with sounds.
Steve was vaguely aware she wasn't resisting. Wetness on his cheeks had him realizing what he'd done and he quickly pulled away without releasing her. Searching her face he noted the blue tinge in her now water eyes was faded and she trembled and clung to his arms. "Quickly," Sylvia forced out through the tears as the current made her head start to swim once more. Steve snapped the collar back on. Her tears of relief had her sagging into his arms when she heard it click closed. She shook all over, her limbs were heavy and unresponsive. She tried to respond to Steve's mutterings of comfort and apology, but she recognized she was fainting and only managed to squeeze his hand with all her fading might as the world faded away.