The dungeon corridor was cold, silent save for the faint hum of enchantments running through the ancient walls. James Potter stood just beyond the entrance to the Slytherin common room, shrouded by his Invisibility Cloak. He hesitated, his breath shallow, his heart pounding.
He had tried to ignore it. Tried to rationalize it. But the rumors wouldn’t leave him, and Sirius had finally confirmed it. Regulus had taken the Dark Mark.
James threw the cloak off with a determined motion, stepping into the dim light of the corridor. “Regulus,” he called out, his voice calm but firm.
Regulus Black, leaning against the wall just ahead, didn’t move at first. Then he slowly turned, his sharp, grey eyes locking onto James with disdain. “You shouldn’t be here,” he said, his tone cold and detached.
“I needed to see you,” James said, stepping closer.
Regulus smirked bitterly. “And now you’ve seen me. Satisfied?”
James ignored the barb, his jaw tightening. “I heard about the Mark.”
For the first time, Regulus stiffened, his smirk faltering ever so slightly. “So?” he said, forcing a shrug. “It’s none of your concern.”
“It is my concern,” James snapped. “You don’t understand what this means - ”
“No, you don’t understand,” Regulus interrupted, his voice rising sharply. “You have no idea what it’s like.” He stepped closer, his cold composure cracking. “What do you want, James? You’re here to play savior? Come to rescue me from the darkness? You don’t get to do that.”
James met his glare, his frustration mounting. “I’m here because I care, Reg.”
“Care?” Regulus scoffed, laughing humorlessly. “You don’t care. You never did. You left.”
“Don’t turn this on me,” James said, his voice growing louder. “You took the Mark, Regulus! Do you know what that means? What it’ll do to you?”
“I know exactly what it means,” Regulus said bitterly. “I know what I’ve done. I don’t need your sanctimonious Gryffindor lecture, Potter.”
“Then when?” James demanded. “When did you -”
“You want to know when?” Regulus snarled, his calm mask shattering completely. “Fine. You want me to be honest? The night you chose her.”
James froze, his mind struggling to keep up. “What?”
“You heard me,” Regulus said, his voice trembling now. “The night you chose Lily. That’s when it happened. When I realized I didn’t matter to you anymore. That I was nothing. You left me, James. You left me, just like Sirius did. You both left me to rot in that house, and I - ”
“I didn’t have a choice!” James interrupted, his voice sharp with guilt.
“You always have a choice!” Regulus shouted back, his voice cracking.
“I couldn’t stay,” James said, his tone desperate.
“Why not?” Regulus demanded, his anger mounting. “Why couldn’t you stay? You could’ve taken me with you. We could’ve left together - ”
“Because of Harry,” James said suddenly, the words spilling out before he could stop them.
Regulus blinked, his fury momentarily replaced by confusion. “Who the fuck is Harry?” he demanded, his voice sharp. “Some new boyfriend? Is that why you couldn’t - ”
“No,” James said quickly. “It’s not like that. Harry is… he’s my son.”
The air between them froze.
Regulus stared at him, his face blank with shock. “Your what?”
James swallowed hard, his throat tight. “Lily’s pregnant,” he said quietly. “Three months along.”
Regulus’ jaw clenched, his expression hardening as the weight of the revelation sank in. “Three months,” he repeated hollowly. “We were together for five months.”
James nodded, shame flooding his features. “I didn’t mean for it to happen. I - ”
“Don’t,” Regulus snapped, his voice sharp. “Don’t you dare try to justify this. You cheated on me. You betrayed me, and now you want to stand here and act like you’re some noble hero?”
“I’m not trying to justify anything!” James shouted, his frustration boiling over. “I didn’t have a choice, Reg. I didn’t know what to do - ”
“Stop lying!” Regulus screamed, his voice breaking. “You always had a choice. And you chose her. You left me behind, just like everyone else!”
“I never stopped loving you,” James said, his voice trembling with sincerity.
“Stop saying that!” Regulus sobbed, his voice raw and manic. “You don’t love me! You fucking left me when I needed you most! You fucking left me when I was at my fucking lowest!”
His sobs turned to gasps, his hands shaking violently as he struggled to catch his breath. James watched, frozen, as Regulus spiraled before his eyes. His mind raced, fragments of conversations from months ago flooding back.
Remus’s calm voice, reading aloud from a Muggle psychology book, discussing the highs and lows of bipolar disorder. Sirius’ dismissive scoff. “That’s not him. Reg is fine. He’s just under a lot of pressure.”
But James had seen the signs. The bursts of energy followed by weeks of silence. The way Regulus’ grades would plummet as he disappeared into himself. How Sirius had avoided discussing it further, brushing off every concern.
And now it was all crashing down in front of him.
James swallowed hard, his chest tightening as he took a cautious step closer. “Regulus,” he said softly.
“Don’t,” Regulus hissed, backing away. His eyes were wild, filled with pain and fury.
“You’re not okay,” James said gently.
Regulus laughed bitterly, his voice cracking. “Oh, really?!”