Sherlock spent the whole journey home showing Mycroft every item of clothing he had just bought, down to the ten slightly varying pairs of underwear. Mycroft, slightly turned in his seat, wasn't listening. He responded appropriately to everything his brother said, but his eyes were slightly gazed. He was so tired.
Sherlock ran upstairs the second they got back and unpacked his new things, folding them as neatly as he could, placing them lovingly into his draws. With a grin at his older brother, who was sitting on the bed, clutching his backpack to his chest, the little boy sprinted back down to talk to his new best friend.
Mycroft collapsed backwards on his bed, his backpack on his stomach. It had been a good day. He'd felt free, felt able to chose what was happening to him. He had been in control. It had been wonderful. But he still felt tears trickle sideways off his face. His stomach twisted in sickening guilt. He was happy away from home. Happy without his parents. Mother was still there, with his father. Who knew what she would have to put up with now he wasn't there to take the brunt of father's anger? What if she needed him? What if the change in routine caused some spiral into a bad depressive stage? What if she tried to overdose again?
He had no right to be happy. He had no right to feel anything he wasn't told to feel. He thought of his father. Maybe they missed him? Maybe his father realised he'd gone too far, and he was just wishing they were home. Maybe he had realised how much he loved them. Maybe he was sorry. But he didn't need to be sorry. Mycroft forgave him for every blow as it happened.
Mycroft launched out of bed, turning manically, pacing around the room, clutching the sides of his head. He was not allowed to be happy. He did not deserve it. He should be at home, atoning for his sins, not here, in this bright, sunny house, with these kind people and at this beautiful school.
Even if he stayed, his life was meaningless now. Now that Sherlock was safe, he had no purpose. It had always been his mission to protect the boy. He had done everything he could to save him. And he wasn't needed anymore. It was pointless.
Mycroft groaned, pulling at his hair, still turning frenziedly around the room. He was worthless, just like his father had always said. His only uses were as father's punching bag and toy, and as Sherlock's protector. And now father couldn't have him, and Sherlock was safe. His meaning was lost. No one would care if he died. No one would notice.
Mycroft dived suddenly for the backpack and pulled it over to the wardrobe. He leant against the door, remembering in flashes the things he had seen from within his father's wardrobe. He reached into the front pocket and pulled out the pocket knife. His hands shook as he flipped out the blade. He held his breath, biting hard on his lip, as he pushed it into his forearm.
Blood beaded out from under the knife, releasing the bitter taste of self disgust and worthlessness from him. He pushed deeper, forcing out more blood, and as it began to run down his arm, he withdrew the knife. Mycroft's head lolled back against the wardrobe door, and he smiled, his breath coming in uneven, shuddering gasps. He felt his body relax. He had paid in pain for his worthlessness, just as he had done so many times at others' hands. Soft laughter shook his chest as he stared blankly at the ceiling, ignoring the blood rushing out of his arm in rhythm with his uneven pulse.
After a while, the bleeding slowed down, and the light headed feeling faded away. Desperate to feel it again, that emptiness, that lack of pain, Mycroft blindly stabbed at his arm, breaking through the slight scab, and pulled downwards, splitting the skin far, far deeper than the last cut. He felt the blood speed up. There. That was better.