You always knew working with Regulus would be difficult. The past loomed like a shadow between you, its presence palpable even after all these years. The war may have ended, but the scars it left—on both the world and you—were still fresh. You had been assigned as Aurors to investigate a series of dark magic attacks, remnants of Vold-emort’s legacy that refused to die. And there he was, the cold, calculating figure from your school days—Regulus, the once-prized Slytherin, a former Death Eater, now standing on the other side.

Even now, as adults, your exchanges were curt, professional. You never forgot the old grudge that lingered between you both, a tension simmering beneath every glance. He had once been the enemy, or at least on the wrong side of history, and that was something you couldn’t easily forgive. But tonight was different.

It had started with an ambush. The dark wizards, remnants of a scattered cult, had cornered you both in an alleyway near Knockturn. Spells flew, curses so dark they hummed through the air with a sense of finality. You and Regulus fought side by side, backs pressed together as you deflected hexes and unleashed powerful counters of your own. For a moment, it was almost like you trusted him. Almost.

But then, things spiraled out of control.

A particularly vicious hex nearly tore you apart, and it was Regulus—quick, sharp, always observant—who grabbed your arm, yanking you out of harm’s way. His voice was tight as he barked orders, cold silver eyes glinting with urgency. You couldn’t help but snap back at him in frustration, the adrenaline spiking.

“Watch yourself next time, Black,” you had spat, breathless as you ducked another curse.

He didn’t respond, but you could feel his judgment in the way he sidestepped gracefully, always two steps ahead. As the battle raged, your vision blurred from the sheer exhaustion, your movements slowing just enough to make you vulnerable. That’s when he stepped in front of you, shielding you with a powerful Protego.