DISCLAIMER: Sherlock belongs to the BBC and the amazing writers Stephen Moffat and Mark Gatiss

WARNINGS: contains drug use and mentions of prostitution (nothing graphic)

Define: Trace

- (verb) Find or discover by investigation

- (noun) A surviving mark, sign, or evidence of the former existence, influence, or action of some agent or event

'I wanted you to see what real courage is, instead of getting the idea that courage is a man with a gun in his hand. It's when you know you're licked before you begin but you begin anyway and you see it through no matter what'

('To Kill A Mockingbird', by Harper Lee)

Mycroft remembers the first time he heard the saying 'you have to be cruel to be kind'. He was ten and Sherlock was three and the neighbour's dog had just been put down: an old, kind, doddery creature that both had loved with the fierce intensity that only Holmes could manage. The task had fallen to Mycroft to explain to his younger brother why he could no longer play with his friend.

"But why?" his little voice had asked, questioning the ways of the world even then. His sharp eyes glimmered with the edge of tears as Mycroft struggled to justify the intentional killing of the dog. Then his mind flashed back to the conversation he had heard earlier that day between his mother and the neighbour and he suddenly know how to put it.

"Sometimes, Sherlock, you have to be cruel to be kind. He was in a lot of pain," Mycroft said quietly, and embraced his little brother.

They were close then in a way that they've never had since: not after the death of their mother and the blame and the fights and this rapid descent into rivalry and arguments. He tries to convince himself it's not his fault, he really does, but sometimes he can't quite forget that it was he that raised Sherlock, he that was the eldest, he who should take responsibility for the spiral his little brother has fallen into. It certainly seems like Sherlock thinks he should.

It shames him to admit that he lost track of Sherlock for those vital years, when he was rising quickly through the ranks of the government and Sherlock was falling just as fast into the seedy underworld of drugs and prostitution and whatever else went on down there.

It takes a single phone call to snap him back into the role of Big Brother.

"Mycroft," Sherlock's voice rasps out down the phone line. Mycroft freezes, sitting like a statue at his desk, dressed as always in a smart suit, umbrella propped next to him.

"Sherlock," he says cautiously. He hasn't spoken to his brother for months, and that was the customary call on his brother's birthday; a date he doubts Sherlock even remembers and certainly never received presents for.

"'Croft," the strange voice utters, and Mycroft's throat tightens. Never has he heard Sherlock sounds so unsure, not in the twenty three years his brother has been alive.

"What is it, Sherlock?"

"Will you- Will you come?" his little brother asks, voice brittle. Mycroft immediately summons his assistant over with an imperious wave of the hand.

"Trace the line," he hisses, then turns again to Sherlock. "What has happened?" he asks.

He can hear Sherlock breathing unsteadily for a few minutes, then he murmurs again, "please come."

"I'm coming, Sherlock, I promise y-" But Sherlock had already hung up.

He swears to himself under his breath for the first time in years, and calls over to his assistant.

"The line was traced to somewhere in East London, sir," she tells him efficiently. "A car is outside and I'm sending the full address to him."

"Thank you," he nods at her, and thinks that his decision to hire the beautiful, odd, under-qualified assistant five years ago was the best decision he ever made.

"I'm currently rescheduling any appointments you have today and tomorrow, sir, as none are too pressing," she carries on, barely looking up from her blackberry. Her fingers skim across the keys faster than he has ever seen anyone do, and he is thankful for her in a way he rarely feels. She has the ability to tell exactly what he needs before he even vocalises it.

"Send me the details later," he tells her, and hurries as fast as is dignified out to the car.

On the way to the address, he tries ringing his brother again, but he doesn't pick up. He worries behind his mask of indifference, but knows there is little he can do until he gets to their destination. His relationship with Sherlock has been rocky for much of their lives; Sherlock resentful of the attention Mycroft received from their parents. Mycroft was the 'perfect child'; the one Sherlock should apparently be more like – calmer and more balanced than Sherlock could ever manage to be.

Ten minutes later, Mycroft's heart sinks as they draw up outside a dilapidated house in a rough neighbourhood. His car draws stares and he knows it is simply a matter of time before local youths attempt to smash it in. He trusts the driver though, a perfectly capable ex-MI6 agent, so tells him to wait there.

"Sherlock!" he calls as he enters the house, taking care around the broken stairs and empty syringes. He spots a teenager slumped in a corner, a tourniquet around his arm and a glazed look in his eyes. He tries, and probably fails, to hide his disgust. He can feel the dirt collect on his polished shoes and resists the urge to hold a handkerchief to his nose. The smell of damp and dirt and drugs and sex is unmistakable. He receives no reply to his call and resigns himself to having to search the entire house.

He is on the first floor when he discovers his brother. He is lying on the floor, an empty syringe next to him, naked as the day he was born. His brother does not stir as he crouches down beside him, and it is only his strong and regular heart beat that convinces Mycroft that he hasn't overdosed. The drugs must have worn off, meaning that he was probably sober when he called Mycroft. Not a drug-addled plea for help then. Something more serious, perhaps? Or a desperate man in need of money for yet more drugs? He will have to wait until his brother awakens before he know for certain.

Mycroft reaches down and hauls Sherlock's arm around him, breathing heavily as he tugs the – far too skinny – man to his feet. Gritting his teeth, he staggers down the stairs and into the car, relieved when Sherlock collapses, still unconscious, onto the seat next to him. Red in the face with exertion, he orders the driver to take them to his home, and vows to lay off the cakes later on.

Sherlock groans as he feels himself rising back to consciousness. He has only a vague recollection of the last few hours – something to do with Mycroft, the painful realisation that the drugs and money had run out and his body was far too sore to risk paying with it again for a few days . . .

"Sherlock?" he hears Mycroft say next to him and he blinks his eyes open. He doesn't reply to his brother and shifts his body into a comfortable sitting position, wincing slightly at the aches in his body. He looks at Mycroft, calculating his last meal, the origin of his suit, the exercise he must have done, five, ten, minutes ago, the thinly veiled concern in his eyes. He frowns at the concern and glances out of the window. He can feel his hands trembling and curses his body for being so obvious about the substance abuse. Then he realises that Mycroft would know anyway, and he finally sees that the scratchy material covering him is a blanket, not clothes.

Mycroft found him naked.

He mentally shakes away the panic and forces his drug-dulled mind to remember what brought him to be sitting, naked, in a car next to Mycroft, who he has barely seen in years. The phone in Mycroft's hand is a vital clue; it is his own (or is now rather, after he lifted it from a shop). So, Mycroft has the phone he was using. It had only a pound or so on it, so the call couldn't have been long. Mycroft looks concerned, so he couldn't have said anything good. What did he say that made Mycroft come running?

A flash of pain and fear filtered through his mind and he started to recall those moments before he collapsed. Someone had threatened him? His landlord? Landlord implies it was money related, which makes sense considering he is naked and sore. He has found, recently, that his body is a good form of payment for many people. But his landlord has threatened him before, so there must be something more, mustn't there?

He shivered as the man left the room. The threats were nothing new, but the look in his eyes . . . He was sore, and alone, and broke, and had no drugs and his mind was running out of control and he couldn't think and he was scared and he really really really didn't want to be there anymore and the only one he could think of to rescue him was the only one who cared for him and he didn't think he had a choice anymore-

His hands were fumbling with his phone before his mind even comprehended his actions. He begged to every deity he had ever heard of that his brother picked up. The relief when he did was so overwhelming that for moments he could only utter his name:

"Mycroft,"

The memories seeping into his mind sicken Sherlock. He was weak to phone Mycroft on such a whim. He can handle people like his landlord, or he could have moved. There are always people who are happy to illegally rent out property, especially to people like Sherlock who have nothing to lose and are attractive and willing.

"We're here, Sherlock," his brother says into the silence. Sherlock looks at his brother's concerned, determined, face, and knows that he will make him clean up. The thought fills him with terror; his mind can't handle the tedium without drugs.

A split second later, and he is out of the car and running for it. His brother reacts too late, and he makes it away.

Mycroft knows he should have expected it really. Sherlock was never one for accepting help. The days after Sherlock leaves slip by in a daze of politics and meetings and worry, but his brother will not answer his phone. He has every person he can spare out in London, trying to track him down, but with no luck. Sherlock is fiercely intelligent, and just as independent. If he doesn't want to be found, he won't be.

It is two months later that he hears from Sherlock again. It is Mycroft's birthday, and he has been ringing Sherlock every day on the off chance his brother will deign to pick up. It is only this day that he does.

"Sherlock," Mycroft says, disbelief colouring his voice. He never expected Sherlock to pick up.

"Happy birthday," his voice says curtly, and hangs up. Mycroft is left standing, looking at the phone, thinking of all the things he could have, should have, said.

The years pass, and Sherlock turns twenty four, twenty five. The phone calls come twice a year as always: once on Mycroft's birthday, once at midnight on New Year's Eve. Then there are the desperate calls, the ones where Sherlock's voice is tiny and weak on the other end, and Mycroft immediately traces the calls and picks him up from whatever seedy place his brother has gotten trapped in. Inevitably, Sherlock will flee again, and none of Mycroft's surveillance can keep track of him.

Mycroft turns thirty one, thirty two, and Sherlock spends the years in a drug induced haze, earning money where he can and by whatever way possible. He has always been able to disconnect his body from his mind, a skill that comes in useful during this time in his life. There are the moments of helplessness and hopelessness, of course, when he has to resort to calling Mycroft, but they are few and far between. He survives.

Sherlock is nearly twenty-six when he overdoses. Mycroft gets a call from a hospital, telling him that a man named Sherlock Holmes has been brought in due to a massive drug overdose, and that he is listed as next-of-kin, and could he come in, please? Mycroft doesn't even bother saying anything to his assistant, but runs – actually runs – out of the building and hails a cab, the first one he has been in since he was nineteen and not nearly as powerful as now. He spends the journey texting his assistant and telling her to cancel anything that day, and he researches overdoses on the internet. He doesn't like what he reads.

He hurries out of the taxi as it draws up by the hospital, barely remembering to fling some money at the driver, and rushes to his brother's room. His assistant, of course, has already found out who Sherlock's doctor is and what room he is in. He looks at his brother, so small and thin in the hospital bed, and recognizes completely, finally, that he has failed in his duty as an older brother.

"Sherlock," he murmurs, and sinks into the chair beside him. His brother is on a ventilator, unable to breathe for himself, and his erratic heart rate can be seen on the monitors.

"Mr Holmes?"

Mycroft stands to address the doctor. "Dr James. How is he?"

"Underweight," the doctor sighs. "His low weight means the drugs had a large impact on him. However, we've administered counter-drugs and we believe he's out of the woods, for the moment."

Mycroft nods, unable to consider the option that his brother will suffer no negative effects from his OD.

"He runs the risk of serious liver damage if he keeps up this lifestyle, and of course it is damaging his heart," the doctor continues. "He was admitted with several lacerations and bruises – none life-threatening," he adds quickly, seeing Mycroft's darkening face.

Mycroft breathes heavily. "Anything else?"

The doctor looks serious and says gently, "There is damage to the rectum and anus, suggesting-"

"I know what that suggests," Mycroft snaps, and shuts his eyes briefly. The confirmation that Sherlock was selling his own body for money for drugs hits him hard.

"I apologise, Doctor," he says a moment later, realising that he may have offended the man.

"That's alright," Doctor James says, and there is compassion in his eyes. "I understand it is none of my business, but may I suggest rehab?"

"He would hate it," Mycroft answers immediately, glancing down at his little brother.

"Do you really think he's enjoying his life at the moment?" the doctor questions quietly. "I apologise, it was just a suggestion," he adds a moment later. "If you have any more questions, please don't hesitate to find me." He nods at Mycroft, and leaves.

Mycroft is left alone with his thoughts, the soft beep of the monitors and the rasp of the ventilator the only other noise. His brother is destroying himself, and Mycroft knows it. He needs help. He sends a quick message to his assistant, and moments later, a reply comes through.

SMS:

The best rehab centre in London:

02089776543

Mycroft bites his lip and dials the number, his thoughts fighting each other all the time.

It'll kill him; he'll hate it.

He'll hate you.

But it'll keep him alive.

And isn't that more important than anything else?

A/N: I hope you enjoyed this, though I know it wasn't the most cheerful of fics . . . Please review, constrcutive criticism is always welcome!

Dreams