Contains subtle Captain America : The Winter Soldier and Agents of SHIELD [up through episode 17, Turn Turn Turun] spoilers.
Just a very short little drabble written at 2 AM, inspired by my boyfriend, who wondered what would happen if Barton was one of the agents who turned against SHIELD... I may expand upon this if I get inspiration.

Betrayal

He fired the shot.

But not at the tac team agent standing across from him.

Natasha watched as the body of the SHIELD agent - a level 2 clearance badge, maybe only recently promoted from intern rank - slumped in the computer chair. His collar, which quickly became covered with the wet, red stain of death, was grabbed and his body unceremoniously thrown to the floor. Crimson drops dirtied the touchscreen and keyboard; calmly, far too calmly, Barton cleaned them off, the blood smearing onto his own skin. The agent's blood.

The man he just pretended to defend.

Instinctively, she slid one foot back, which put her body into a grounded fighting stance. Her right hand shadowed one of her twin pistols - loaded with real lead, not sleepers - while her blue eyes found the stormy gray of her partner's... or, more accurately, her former partner. Beyond Barton, the tac team paid little attention to her as they went about securing the room; locked doors, fried security, guarded windows... there was a man in every corner and another with any sort of security measure SHIELD could think of. They, the enemies in SHIELD clothing, drifted as if she wasn't there. Any other time, she may have thought that a move out of respect... perhaps even fear. Right then, however, as Natasha slowly pulled the gun into her dominant hand, she read the ignoring of her as a tactical move. None of those level five-to-six agents stood a chance against her. The room knew it.

Barton, on the other hand...

"Clint?" Her voice was controlled. Level. Yet the internal voice in her head wavered, as did some ingrained sense of place and reality, as Natasha moved so there was another computer chair in between herself and the Hawk. The gun was in her right hand; soon, the left handed pistol joined its sister. "...what is this?"

He lifted his pistol. Unlike every other time she had seen him do so, his right arm didn't lift in the ghost motion of firing an arrow. She put her fingers on her respective triggers and raised the weapons to defend herself. As she exhaled a slow breath to aim, a weight fell onto her shoulders, and a gripping fear rose into her throat. Clint Barton. Hawkeye. The man to who she owed her life, that who she had the indescribable loyalty, that urge to serve and protect. That man, now a murderer, who shot an innocent faculty member that had managed to survive the initial onslaught by the tac team that littered the room.

"You ordered that air strike on Rogers and me," Natasha murmured. In place of the regret she had expected was a rumbling, an anger that sparked in the back of her mind and grew until her teeth were ground, her knuckles were white, and her breath felt hot. "Didn't you?"

It was a question she knew the answer to. Like a trigger, the words changed Barton's expression. Slowly, where his impersonal and perceptive eyes had once looked to take out a tac team that they - herself and him - had stumbled upon, his eyes gained a dark, twisted light. Joy. His mouth turned up in a mad, crooked smirk that hinted at a deep cruelty that she had never seen from him before.

"Hail Hydra," and he fired again.