You are right that there aren't any direct references in the episode to suspect he used a drug.
But let me try to convince you:

First: The rubber stress ball:
Before Sherlock went to the roof, he kept on pumping and throwing that ball around.
Maybe that was to increase his blood flow so the drug would spread rapidly through his system once he snuffed it up.
Increased muscle activity widens the arteries.

Second: Intranasal:
 There aren't many ways to administer a drug (aerosol, oral, intranasal, sublingual and rectal),
but the writers of Sherlock have already showed that they can be creative with this.
In HOUNDS (as you mentioned) Sherlock keeps asking himself: "How did the drug get into our system?".
In that case the drug was an aerosol.
Maybe the writers learned about intranasal administration as a possibility when they researched it.

Third: Sherlock's tearing up:
Right after the snuffing sequence in the picture, we get the emotional scene with John in which Sherlock can't keep the tears from flowing.
Come on, Sherlock has never been an emotional type.
Plus, why would he cry if he knew he would survive the fall?
By snuffing in the drug, he temporarilly increases his nasal secretion and lacrimation.

Fourth: the empty house:
In the written story of the empty house by Doyle, Sherlock explains to John why he didn't want him and anyone else to know he was still alive:
so his other enemies would move more out in the open.
In the story he says nobody else knew he was alive except Mycroft.
Now, i don't think Mycroft knows about Sherlock still being alive because of the sibling rivalry, Sherlock would never accept Mycroft's help.
But Molly never existed in the stories of Conan Doyle.
What if only Molly knows about Sherlock not being dead. It makes everything a lot simpler:
The doctors of St Bart wouldn't have to be in on it, no homeless network involved, no Mycroft involved.
The less people know about it, the less chance word gets out Sherlock's not really dead, just like Doyle intended it.

Fifth: Molly's a doctor, doctors can prescribe drugs.

Well, that's what I wanted to say.
The theory definitely has some holes and there are still things unexplained.
(but maybe the cyclist was just a cyclist John happened to bump into) 
I could also be wrong about the type of drug used, TTX just seems the best drug to cheat a doctor.
Maybe people reading this have a different drug in mind? (let me know)

Oh, and could you post the link where you found that they're going to show the solution in a pre-credit scene of S3E1, I can't find it.
 

Last edited by Arthur Doyle (April 14, 2013 3:45 pm)

Interesting idea.
I have to say that I thought it was odd that Sherlock appeared to be crying, although it could have just been acting to convince John. (Myself, if I had been up on that windy roof, my eyes would have been tearing and my nose running and red.)

When I observe the way he falls, I doubt there was a relaxant. Or it would have worked just later - very exactly on time ;-)

I do like this idea but I think the main problem is that the writers have said all the clues were there, there won't be anything we could not deduce. And there is no point at which a drug is planted or suggested. Is there? While yes there is in HoB, its a very different drug. The only other possibilty I can see is the mercury poisoning but mercury poisoning doesn't relax you.

If he's taken a drug then nasally is deffo the best option here, much faster than anything else he could have done.

Actually, a muscle relaxant might have helped him survive the fall. He'd also need to invoke cartoon physics because he's still falling a little too fast to survive. But being relaxed on impact will help a little, that's why young kids often don't hurt themselves so much when they fall from a height.

Last edited by beekeeper (April 15, 2013 6:54 pm)

I don't want to be too thick here about ways to administer a muscle relexant, but look at TGG and what Moriarty did: subcutan
Maybe Sherlock used several plasters. We know that he uses nicotin patches.

Okay, this is so far my favorite "long shot" theory...I'll be shocked if it turns out to be true, but I sort of love it anyway...

Any chance Sherlock found a way to administer some of the Baskerville drug--we know he obtained some an episode ago, and him being him he might well have hung onto some--not to John but to Moriarty on the roof? The drug we've already encountered that makes one paranoid, fearful, extremely succestible to suggestion, and prone to hallucination?

I read someone's post suggesting that he'd injected the rubber ball with the stuff and taken that moment when he sort of oddly grabbed Moriarty's lapels and sort of shook him to squeeze the drug out of the ball onto JM's clothes. I agree that that grab-and-shake (followed by one of the more inane Sherlock lines of all time, "You're insane"--though I loved JM's puzzled, "you're just now getting that?" rejoinder) is extremely out of character for Sherlock, and I haven't seen it often mentioned among the "Sherlock did something very out of character" suggestions. What was that supposed to accomplish?

Anyway, following that moment, a couple of things happened...we saw a lot more of Sherlock sort of panting and breathing hard when not close to JM. And then, after the almost-jump-I-don't-have-to-die-if-i've-got-you bit, JM sort of starts losing it...in the end there, it really kind of looks like he's having visions or something--notice his sort of weird blinking, and saying, "You're me"--it could be just a realization thing, of course, but what if he's actually seeing himself in Sherlock through his own eyes, after Sherlock has just told him again and again, "I'm you. We are the same."

Yeah, I know--TOTAL long shot, explains very little, and really would give Sherlock only the smallest advantage, but maybe he thought that might be all he needed?

(This also addresses Sherlock's unwonted emotionalism at the end in his conversation with John--if JM had the stuff on his clothes and was inhaling it that way, Sherlock would have gotten some as well...)

I'm not saying I believe this one...but part of me sort of likes it. Any thoughts? About this, or about what that whole grab-by-the-lapels thing was about, or all the panting and hyperventilating?

I can try to address the second part of your concern. Molly's there to declare him dead. She's a coroner and knows him personally so she could also ID the body. It's rather easy for Sherlock to have St. Bart's declare him dead.

Well, yes, I agree with you. I just meant that would explain how St. Bart's would declare Sherlock dead, not the extent to which Molly played a role.