Sherlock can feel it pressing down on him, the darkness, the black mood - it had only been a matter of time before it happened. Living here with Mycroft is bad enough, but he can't bear the thought of his brother coming home and finding him shaking and broken, not again. He lays there, on the sofa, dreading the moment Mycroft comes through the door to find him like this. Finally, that thought goads him to get up and walk to his bedroom.

The detective digs out a pair of jeans and an old hoodie and puts them on. Kneeling, he fishes around under his bed and finds some old trainers and dons them. It's not hard, after that, to flee Mycroft's home. He evades both the CCTV network and the guard across the way and, in just a few moments, he's walking the streets of London safely anonymous.

The sun is shining and birds are singing, but all Sherlock sees is grey, all he hears are his own miserable thoughts. He ducks into an alleyway to get away from the crowd that is growing on the streets and leans heavily against a rough brick wall.

If only he could cry! Sherlock's read that crying is supposed to be cathartic. What he wouldn't give to spill out his pain in hot, burning tears, but he's never cried, not even as a child. He's a sociopath, that's what the doctors had said just before Mummy called them idiots and Father declared them incompetent. The doctor's were right, if not, why can't he cry?

The detective slides down the wall, his hoody riding up and his back scraping against the rough brick - he doesn't care, barely even notices the physical pain. He can't cry, but there is another path to relief. A quick fix would ease the pain, at least for a little while. Sherlock makes a tight fist and his fingernails did into his palm, drawing blood. Is it worth it, giving up everything he's working for? He shakes his head.

From experience, he knows that, if he can get through the next three days, the blackness will lift. It won't go away entirely, this heavy depression, but it will be bearable. Three days. He'll never make it that long, not on his own.

Sherlock doesn't call Mycroft, that is never an option. He doesn't call his parents either, he doesn't want to break their hearts again. There's no one. No one. He's alone.

Sherlock looks up at the sound of a siren and sees a police car pass by the end of the alley. Without thinking about it, he pulls out his phone and dials. Someone picks up on the other end and says hello. The detective tries to talk, but can't, not at first. The voice says hello again.

"Lestrade," the broken man chokes out. "I can't... I need..."

"Sherlock?" Greg asks, "What's wrong? Where are you?"

Even in this state, Sherlock can deduce Lestrade's actions - he's shoving folders into his desk drawers, locking them and grabbing his keys.

"Please, Lestrade." The young man can't manage more.

"I'm on my way," Greg reassures. "Just tell me where you are."

Sherlock pulls out his mental map of London. It's not perfect, not yet, he's still learning the backways and rooftops, but it's adequate to this task. He tellls Lestrade how to find him. His hand drops, but he doesn't hang up. The detective can hear the other man talking to him, distant and faint.

"Don't you ring off, Sherlock. Keep talking. Observe. What do you see around you?" Lestrade sounds calm, but worried as he issues instructions.

Sherlock lifts the mobile to his ear and obeys. He looks around and makes deduction after deduction. Every time he falters, Greg asks a question to get him talking again. Finally, a cruiser pulls into the alleyway and comes to a halt. Lestrade climbs out of it, phone still in hand. He crouches down in front of Sherlock and gives him a weak smile.

"You look like hell, son," he notes.

The young man returns Lestrade's smile with a broken one of his own. He can't manage any more words, he'd used them all on the phone earlier.

Greg reaches out a hand and waits for Sherlock to take it. "Come on, let's get you out of here."

"Where?" It's only one word, but Sherlock gets it out.

Lestrade sighs. "You don't need to be alone. Can I call someone? Family, friend? Take you there?"

The detective shakes his head.

"Of course not." Greg sighs. "My family is out of town for the week. You'll come home with me." There's no room for argument in Lestrade's words.

Sherlock takes his hand and Greg helps him to his feet and into the cruiser. The silence between them isn't comfortable, but it's not painful. It fills the spaces, though, and starts to push the blackness away.