So, I’ve been doing a bit of digging. I’ve read loads of theories before about Reichenbach, some were absolutely dreadful, some were pretty awesome, but beyond a few vague guess, I’ve never seen anyone properly explain the fall. They’ve explain Moriarty’s plans down to insane lengths, delving deep into Hansel and Gretal and making justifiable leaps in logic to explain what Moriarty was doing and how he was doing it, but none of these brilliant theories have any real explanation of the how he survived. Then the survival theories, they all either involve the squishy ball, drugs or something breaking his fall.
Now, this will be an unpopular opinion, but I think any theory that involves something breaking Sherlock’s fall is stupid. Sherlock had no possible way of knowing where the sniper was, so would have no idea what the sniper could see. If he was going to plan something as elaborate as faking his death by falling, he wouldn’t have used something as risky as a fall breaker.
The squishy ball is good, but again, it’s risky. He’d have to make sure it was tied to his arm, and that might make it obvious to anyone who saw his arm, especially to Moriarty.
So, personally I think it was drugs. More specifically, I think Sherlock poisoned himself. There are a few poisons, namely Poison Hemlock and TTX, that cause full body paralysis. TTX is more likely, as it’s more likely to be available in hospitals for study and research (which, I believe, St Barts is).
Now, for the past few days, something has been bothering me. I could swear that I knew of a fairy tale where someone was poisoned with Hemlock, but I couldn’t work it out. Today I discovered what it was. It was obvious. Hemlock isn’t mentioned by name, but it still fits the bill. Snow White. Snow White was given a poisoned apple and fell into a deep sleep until true love’s first kiss woke her up.
Now, I bet you can tell where I’m going with this now. In all the stories, the apple that the evil queen gave to Snow White was red. Sound familiar?
So, Sherlock knew that he was going to fall. He probably knew that meant a metaphorical and a physical fall. He metaphorically fell when it came out that he was a “fake” (even though he wasn’t) and he physically fell when he, ya know, fell.
I think, when Sherlock realised that Moriarty was using fairy tales, that’s when he realised how he could survive the fall. He had to become Snow White.
On the roof top, he had already taken the drug. He knew that Moriarty would go to whatever lengths needed to ensure a victory. He also knew that if Moriarty won, Moriarty would become bored again. So, I think he tested TTX on himself, worked out how long paralysis would take and how long it would take to ware off. He knew the correct amount and knew how much would be an overdose because, well, he’s Sherlock. I think he injected himself with the poison with the intention of being on that roof for a certain amount of time. He went up there, making sure that he would have to fall, making Moriarty either win and be bored, or die. Then he timed it perfectly, so that paralysis would take over just as he began to drop. TTX also lowers the heart rate dramatically.
As he was falling, the paralysis stops his muscles from contracting, keeping them relaxed, ensuring he survives the fall. It would render him in a near death state, probably for hours, maybe even days. Plenty of time for Molly to fake the death certificate. Hell, plenty of time for Molly to believe he’s dead and write a real death certificate. Then as it wore off, time for him to escape and disappear.
I think the key to how Sherlock survived, the one thing that Moffat said we all missed, was the red apple and the red apple being the link to prove how Sherlock survived.