Regulus never thought an empty bed would be the thing that finally pushed him over the edge. He was taught not to cry; not to scream, and most certainly not to beg. But he found himself doing all three in Sirius’s abandoned bedroom. He pleaded for the blankets to bring his brother back, he screamed at the pillow to make sure he stayed gone. Nothing changed the bleeding broken beating monster in his chest. If he had a knife Regulus would carve the useless thing from his body. Perhaps gift it to his brother, to show no matter what his actions were, he never stopped loving him.
Violence was the only language Regulus knew how to speak; he couldn’t understand the gentle tracing of fingers on skin the way he could a vicious slap to the face. Sirius used to be fluent as well but the longer he stayed away, the longer Potter infected him with joy and love, the less he understood. Regulus was left alone with bloody hands and words that his brother no longer understood. Sirius didn’t know that Regulus had allowed their mother to turn him into a puppet, make him the heir she wanted, all so he could run off to the Potters. Sirius didn’t know that Regulus had killed more people than their combined ages. He didn’t know the true suffering Regulus had undergone to become the angry broken shell of the boy he used to be. And that hurt more than anything else. Regulus missed his brother so sharply, it felt like his brother had taken a piece of Regulus in his escape. A fundamental piece that would allow him to breathe.
He couldn’t breathe anymore. The anger was strangling him, burning his lungs and wrapping its claws around his throat. He vaguely felt his knees hit the floor. He barely felt his nails cut into his palms. He didn’t feel it at all when he pointed his wand at his chest. He felt it when the wand flashed red, and his body was consumed in agony. He held it for seven minutes. Just barely stopping before he damaged his mind irreparably. He took long gasping breaths. He stayed on the floor like that until Kreacher found him. The house elf gasped at his pitiful state.
A gentle hug was not what Regulus was expecting, but he melted into Kreacher’s arms in relief. The elf rocked him the way he did years ago when Regulus came back from particularly rough stays at his cousins' house. Kreacher allowed him to remain on the floor for a few minutes before he hefted him up. Regulus moved like a zombie thinking of nothing but the painful beating in his chest. Kreacher moved him to his room, cleaned the sweat from his face, and tucked him into bed. “Mistress has gone to bed. Master Regulus can rest now.”