A/N: This takes place immediately after the events of "Tension Makes a Tangle."

Warnings: Slash. Adult content. Angst. Drug use. Violence. Swearing.

Disclaimer: Not mine. Title comes from a Depeche Mode song that I think fits John & Sherlock's situation at the moment, but this is not a songfic. (It's a great song, if you aren't familiar with it, check it out!) No profit here, just love. Please Mr. Gore, don't sue me, unless you want a 12 year old car with faded green paint.

Beta: The always wonderful Jarri Scythe!

Shake the Disease - 1

I hung up the phone and sank down into my chair, slightly shocked at the news my sister had just given me.

"John, what's wrong?" Sherlock was looking at me worriedly from his reclined position on the couch.

"That was Harry...She's checked herself into rehab. She...she said she won't be allowed any visitors for two weeks, but after that we can come and visit. It's a thirty day in-patient program, with follow-up outpatient counseling."

Sherlock and I looked at each other. Neither of us seemed to know what to say.

After a moment I shook myself, saying, "I've got to get to work, I'm late."

Sherlock didn't respond. I realized that we hadn't had a chance to finish our conversation about our relationship, but getting Harry's phone call had thrown me off balance and I didn't really feel capable of continuing it.

In a few minutes, I had finished getting ready and was heading for the door. Sherlock was still on the couch, staring at the ceiling, as he usually did when he was sulking. I felt a little guilty. I realized that on some level I was running away, but my tardiness for work was not a lie.

"I'll see you tonight, yeah?" I called as I hurried by.

I was answered with silence.

I ended up staying late at the surgery to make up for the time I'd missed in the morning. I found myself trudging home late, feeling tired and anxious. I was actually dreading the coming confrontation with Sherlock, although I knew we needed to resolve the issues that we'd been discussing before we were interrupted by Mycroft and then Harry.

I made my way up the stairs, a little surprised that no light was coming from our sitting room. Even when Sherlock left the flat he usually left a light or two on.

I came in, and fumbled for the light switch and saw that Sherlock was draped on the couch, but now in his pajamas and dressing gown. He didn't react at all to my arrival.

"Hey there," I said, "did you get some sleep today, I hope?"

There was a indecipherable sound from the couch.

"What do you want to do about dinner? It'll be my treat," I called from the kitchen as I looked in the cupboards. "I can throw something together maybe or we can get takeaway?"

There was only silence.

"Sherlock? Are you angry at me?" I was feeling a bit guilty at having left with our conflict unresolved.

I came out of the kitchen to talk to him face to face. Immediately, something seemed wrong. I've seen Sherlock "zone out" when thinking about a case or sulking, but this seemed different. In those cases, he would snap vigorously at any attempt to pull him out of his mood. As I approached the couch, he didn't seem to be aware that I was even there.

"Sherlock?"

Still no response.

I leaned over him. His eyes were open, but were glassy and unfocused. He had a slight, dreamy smile that I had never seen on his face before. It was a far cry from his "thinking" or "pouting" look. My heart began to pound.

"Sherlock?" I shook him gently.

He emitted a shallow sigh and seemed to focus on me for just a moment before drifting off again.

"John..." he murmured.

"Oh dear God Sherlock, what have you done?"

"Mmmm..." was his response.

I grabbed his left arm, and rucked up the sleeve. There was a fresh needle mark. I dropped his arm, horrified, and ran to the bedroom for my medical bag.

I came back and took his vitals. They were significantly depressed, but not critically so. My panic eased just a bit, but by no means ended. Sherlock remained blissfully indifferent while I checked him over for any additional needle marks. Thankfully I didn't find any. I didn't think he could have been using regularly without my having noticed, but I didn't want to take any chances.

Once I was satisfied that this appeared to be a brand new relapse I shook Sherlock again.

"Sherlock, what did you take?" I had a suspicion, but I wanted to confirm it.

He didn't respond, off in his dream world. I shook him harder and got a disapproving mumble.

I slapped him hard across the face.

His eyes focused on me in surprise, "John?"

"Sherlock," I said, my voice trembling slightly with anger, "what did you take?"

He smiled dreamily, "Heroin."

I shook him again, "How much you bastard?"

"The usual."

I began to panic again, "How much is that?"

"Fifty."

"You idiot! You've been clean for years! That's way too much for your system to handle."

He waved his hands dismissively.

"When did you take it?"

I had lost him again. So I slapped him, again.

When he refocused I repeated, "When did you shoot up?"

He looked a little confused, and closed his eyes, "You didn't come home. You don't want to be with me."

"What? You feel a little bit sorry for yourself so you shoot up some smack?"

He had drifted off again, and I realized that attempting to chastise him right then was pointless.

Instead, I quickly prepared a syringe of opiate inhibitor. I had gotten in the habit of always having some with me in Afghanistan, and continued the practice of having it handy since I'd returned. I found a vein in his right arm and quickly injected the drug.

It only took a moment or two before it took effect. Sherlock groaned and began sweating. He tossed and turned, and then leaned over and vomited on the floor. I kicked myself mentally for not getting a bucket ready first.

After he was done Sherlock passed a shaky hand over his face and looked at me with a bit more clarity than he'd had previously.

"Sherlock, I've given you an opiate inhibitor. It doesn't last very long, so you're likely to get high again, but not nearly so. I want you to go to bed while I clean up this mess. And we are going to talk about this tomorrow when you're back in your right mind. Do you understand me?"

He nodded and I helped him off the couch and into bed. I brought him a glass of water, then went to the task of cleaning up Sherlock's sick.

To be continued...