It is called Lovingkindness, the newest street drug to make bored teenagers froth and writhe in dirty gutters as they gasp out their dying breaths. Similar in chemical profile to methamphetamine but with more of a 'kick', as dealers say. The high lasts 2-3 hours and causes euphoria, increased energy, racing thoughts, tachycardia, and, in the event of an overdose, symptoms similar to rabies, with hydrophobia, poor muscle tone, and paranoia. Withdrawal side effects include nausea and vomiting, irritability, crying jags, confusion, convulsions, and severe dehydration. Just another way for junkies to get a fix more potent, more vicious, and more exciting than the last.

These are the facts running through Greg Lestrade's mind as he looks at two lavender tablets perched before him on the table, prim and beguiling beside a glass of water. With a pained smile he realizes that he looks nothing like the stereotypical clubber or candy raver; he seems more suited to cigarettes and whisky than some bizarre new intoxicant whose pharmacological properties are barely known at best. But he was always one to play fast and loose with his health, and now he's stopped giving a shit about propriety and even, at times, legality. If this is the new high he can chase to its conclusion, the new low he can sink into, then so be it.

His relationship with Mycroft – with its jagged boundaries, its long dry seasons when they are both working absurd hours, its crushing loneliness and secrecy and quiet disappointments when he is stood up, again and again, because of government obligations – is failing at best, murderous at worst. A string of homicides that made New Scotland Yard look like a troupe of clowns with police badges has embarrassed him to the core, and the dazzling conclusion that nearly killed his freelance detective was a further black mark against their force. If a man with no forensic training, no police academy degree, nothing but a freakishly large brain can solve murders that confound an entire squad of highly-ranked officials … well, it calls into question just how much he is needed.

Anyone with this much ennui, this much self-doubt and shame, would want to disengage for a bit, and 2-3 hours of hyper-focus and happiness and superhuman stamina sounds like just the ticket.

He barely tastes the sharp chemical tang against his throat, diluted as it is by 10 ounces of water. Mycroft is out for the night, his phone is off, and all the doors are locked. He won't be driving or operating heavy machinery or even using the stove. All the precautions are in place. He carefully picks his way to his bed and waits.

Soon enough his eyes are alight with colors, his body buzzing with every sensation at once. He imagines this is what it feels like to be torn apart by a black hole, reformed into some sort of nothingness with a sentience equaling everything. Suddenly he wants all, he wants omniscience and omnipotentce. He wants milk beyond milk.

Downstairs the fibers of the carpet sway, and he can hear them. Someone is coming up the drive, as evidenced by the sound the shadows on the blades of grass in the front lawn. He tries to sit up but his muscles fail and he laughs, he laughs because the world is so futile and so tiny and he is everywhere at all times.

It's a millennium and a half before there is a tall comforting figure standing at the bed. He knows Mycroft knows before he even breathes, that he knows what has happened and that Lestrade has given up. The cilia in his boyfriend's lungs murmur to him and he starts to cry, because everything has a voice and everything is leaving him at the speed of forgiveness.

Mycroft holds him and pets his hair and gives him a glass of water, an entire ocean in his microscopic hand. "You'll be okay," he murmurs and Lestrade can feel the years of addiction weighing down on him, from his little brother, from everyone he has loved. He is just another tick mark in the syringe of Mycroft's self-control, just another milligram of that ice water that inhabits his veins. And he is so sorry, so sorry, so sorry. He tries to say so but it comes out as vomit instead.

When he wakes, he is clean and clothed in Mycroft's silk pyjamas, swaddled in blankets like a newborn. The civil servant is sitting on the edge of the bed watching him with those ancient hawk's eyes, and he can almost taste the disappointment.

"I'm so …" he croaks, but Mycroft just sighs.

"It's okay, Greg. We'll get you to a detox center. We'll go into counseling. The utmost of discretion, I assure you. Take a month or so off work, take some time away. We'll make it work."

He nods his leaden head and hopes that's enough, because he knows it must work, because with a Holmes all things must work or they will be thrown away. Mycroft just leans over and brushes his hair back, pressing a kiss to his weathered brow. His breath is warm and minty and Lestrade feels even dirtier than before.