Like every other Sherlock fan, I started theorizing within seconds of that final sequence. I rushed into a Skype call, where my friends and I batted ideas back and forth.
These were the facts, as we saw them:
- Sherlock Holmes is a genius and he had time to prepare;
- He chose the place for the final fight;
- He potentially (via his brother Mycroft) has unlimited funds and the compliance of London authorities in staging his own death;
- He definitely (via Molly) had the ability to walk out of a mortuary without questions being asked.
The rest is open to interpretation and observation. Assuming that was no ghost spotted after his funeral, then Sherlock must be alive and well.
Moffat and Gatiss are aficionados of the Conan Doyle stories, so they frequently sprinkle obscure canon references throughout their versions. The literary Sherlock survived the Reichenbach Falls by using Japanese Baritsu (an imaginary marital art). I wondered if this new Sherlock had employed some kind of Asian meditative technique to stop himself being hurt.
Alternatively had he worn a physical harness, which cushioned or broke his fall? His coat was certainly bulky enough to conceal one.
I then recalled that he had been very good at Parkour, as evidenced in the very first episode. A lower roof was glimpsed each time he peered over the parapet. Could he have used his traceur skills to land in a roll onto it, then quickly make his way to the ground?
If not, then how about a substitution? Mistaken identity had been a running theme throughout both series 1 and 2. In The Great Game, a young girl screamed at the sight of Sherlock. Moriarty had somehow linked the detective's face with her kidnapping. Meanwhile, in The Hound of the Baskervilles, there was talk of human cloning. Sherlock certainly had ample opportunity for puzzling over that.
Other fans have come up with a vast array of ways in which he could have survived. They range from the bizarre (it was aliens a la Life of Brian) to the in depth and feasible. It's been pointed out that a bus was parked there just before, maybe delivering a cast of actors to keep Watson back and spirit Holmes away.
What about the truck filled with plastic bags, which replaced it? Did it provide a soft landing from which Sherlock could then roll onto the pavement? Or did it deliver, then carry away a mattress, to be inserted into the rectangle chalked onto the slabs?
What was the favor that Sherlock asked of Molly? Did she merely help him escape the morgue, or did it go deeper than that? Did she provide a corpse in a Sherlock mask or cut off a human hand at the wrist, for him to hold, so that Watson wouldn't find a pulse?
All of these and more are being proffered and discussed by fans desperate for the next installment; myself very firmly amongst them!