It was raining outside, the usual grim atmosphere of Number 12 Grimmauld Place settling over them like a heavy fog. The Order had reconvened in Sirius’ old home, the only safe place left to gather. Harry sat in the parlor, staring at the dark wallpaper and dust-covered furniture when a voice, sharp and elegant, suddenly broke the silence.
"What? Who are you?"
Harry turned sharply toward a portrait he hadn't noticed before. The boy in the frame was young—no older than seventeen—with dark hair and sharp grey eyes that looked startlingly familiar.
"I'm Harry... Harry Potter. Who are you?" Harry asked, sitting up straighter, unsure if this was another cursed painting.
The boy in the frame blinked, head tilting slightly as though studying him.
"I'm the owner of this house."
"Oh," Harry breathed, realization dawning on him. "You're Regulus. Regulus Black."
Regulus straightened proudly.
"Indeed. And what, may I ask, is a Potter doing in my house?"
Harry's mouth opened, ready to explain, but before he could speak, Sirius stormed into the room, followed by Lupin and several other Order members.
"Harry, what are you—" Sirius stopped, freezing mid-step as his eyes landed on the portrait.
For a long moment, there was only silence. Sirius' jaw tightened, emotions flashing rapidly across his face—anger, shock, pain.
"Reg?" he whispered, voice hoarse.
Regulus smirked softly.
"Well, well. Look what the dog dragged in."
Sirius let out a shaky breath, stepping closer to the frame.
"You're—how are you here? I thought you were dead."
"I am," Regulus replied, his tone softer now. "But my mother was thorough in her enchantments. My portrait was painted before I... before I went to the cave."
A heavy silence settled over the room as everyone exchanged glances.
"The cave?" Lupin asked carefully.
Regulus' expression darkened.
"The cave where I went to die. Voldemort's horcrux. I found out what he did—how he made himself immortal. I took the locket, replaced it with a fake. But I didn't make it out."
Harry leaned forward, heart pounding.
"You knew about the horcruxes?"
Regulus' eyes met his.
"I did. I tried to stop him. Alone."
The Order members were stunned. Sirius' hands curled into fists as he processed the truth, eyes glimmering with something close to grief.
"Why didn't you tell anyone?"
"Who could I tell?" Regulus snapped, eyes narrowing. "I was already deep in the Dark Lord's circle. Who would have believed me? You? You hated me. Mother? She would have turned me in for treason."
"You wouldn't have been alone," Sirius whispered, but there was no conviction in his voice.
Regulus looked at him sadly, the bravado slipping away.
"I always was."
The room was thick with tension. Then Hermione, quiet until now, stepped forward.
"You were trying to help. You should be remembered for that."
Regulus blinked, startled by the kindness.
"Doesn’t matter now, does it? I'm dead."
"That doesn't mean we can't honor you," Harry said firmly.
Sirius' voice was rough when he spoke again.
"Where did you die, Reg?"
Regulus looked down, almost ashamed.
"In the lake. The Inferi dragged me under."
Sirius swore under his breath, pacing.
"We can get him out," Sirius muttered, determination burning in his eyes. "We will get him out. Give him a real burial. Not let him rot in some cursed lake."
"Sirius..." Lupin started cautiously, but Sirius shook his head.
"No. I'm not letting my brother stay there. He died trying to fix what that monster did. He deserves better."
Regulus' eyes widened slightly at Sirius' words, a flicker of something softening his sharp features.
"You'd do that for me?"
Sirius looked up, meeting his brother's gaze.
"You're still my brother, Reg. Always."
The room was quiet again, but this time the silence was filled with something different—respect, understanding.
"Then find the locket," Regulus whispered. "Finish what I couldn't."
Harry stepped forward, determination burning in his green eyes.
"We will. I promise."
—
Weeks later, when Harry stood beside Sirius at a quiet, hidden grave Sirius had made sure was secure and free from prying eyes, he knew Regulus had finally found some peace.
Sirius knelt by the headstone, running his fingers over the carved name.
"You're not forgotten, little brother."
Harry smiled softly.
"We’ll make sure of that."
And as they left, Sirius glanced back at the grave one last time, a weight lifted from his chest for the first time in years.
Because now, Regulus wasn't just the "other Black brother"—he was a hero.