I do not think John was drugged. In that moment Sherlock counts on what a normal reaction to seeing a best friend standing on the roof delivering "the note" would be. Shock..surges of adrenaline...a hit from the bike to disorient...the touch of the wrist to note no pulse (that would be the rubberball technique)...and then Molly Hooper certifying the death of Sherlock.  All this-the magic trick Sherlock eluded to.

Someone who may have been drugged was Moriarty...the scene on the roof where Moriarty seems to unravel psychologically.  It's a quick leap from functional psychopath to suicidal psychopath.  Where was it administered?(When Sherlock grabs Moriarty and hold him out over the roof to get him to divulge his friends that are targets probably) What was it? (the aerosal from Hound probably)

I have a theory that I will post and would love to have you guys add on or detract from it.  My family is having a Sherlock Party and we have to submit how he did it.  The one closest to Sherlock's plan wins  We also have to answer a few more questions like is Moriarty really alive?  (if you have any good questions let me know- I have the task of making them up)
 

It has come to my attention that we need a good theory.
Well here it is.

First, sherlock slowed his heart and pulse to an almost state of death. Next, he waited untill he could feel the rate of his heart fading, his life floating away and pins and needles all over, and then jumped. Snagging his foot on the building, he broke his leg and smashed his head on the truck below, just above ground. Because of the pins and needles, he felt no pain and crashed harmlessly on the ground. Blood seeped from his wounds giving the impression he was dead. Blood everywhere, skin as white as ice. seemingly dead. they assume he is dead because, afterall, no-one likes to see some distant child's role model lying on a surgery table being cut open to be sure they have kicked the bucket(or snuffed it, as he did with Henry Baskerville's ciggarette in the preivious episode)

to jaynosan, 
you have good theories! but the first one i think was better, he couldve used a drug to slow his heart rate so yours could be correct....? but there are also theories on youtube too so check them out before tomorrow!!!! x

TeeJay wrote:

Sorry for abducting the thread, but I'm in the mood for something more humorous this morning.



And then the reunion scene between Sherlock and John:

John: Say, Sherlock, how on earth did you survive that fall?

Sherlock: Oh, you know, easy. Didn’t I tell you? My coat has magic qualities. It gives me the ability to fly. Like… like that bloke from the comics.

John: Spiderman?

Sherlock: No. Spiderman couldn’t fly, could he? The— the bat guy.

John: Batman.

Sherlock: Yeah, that’s it.

John: Wait a minute, you flew off the roof? With your coat. Then how did I see you lying dead on the pavement?

Sherlock: Identical twin. Had to bribe him to do this. Sorry I never mentioned him. We don’t get along.

John: (shakes his head) This takes ‘bizarre’ to whole new levels.

 
The first time I saw that brilliant gif I nearly wet myself laughing! Thanks for sharing it again!

I still think that whatever used by Moriarty to knock the guard out in the Tower of London, might've been the stuff that came out of his fake gun, to knock himself out.  A sniper probably shot a blood pack on his collar.
And I'm glad I'm not the only one who thinks Sherlock drugged Moriarty on the roof.  Moriarty's personality change was obvious.

Yes.