BBC’s Sherlock adapted some of the detective’s most memorable moments, including his apparent death in "The Reichenbach Fall". Like in the source material, Sherlock came back after that, but how? The adventures of the world's greatest detective have been adapted to film and TV multiple times, and one of his latest TV versions was Sherlock, with Benedict Cumberbatch as the titular character and Martin Freeman as John Watson.
Sherlock premiered in 2010, with season 2 arriving in 2012 and leaving fans with a big cliffhanger: in order to save John, Mrs. Hudson, and Lestrade, Sherlock had to die by jumping off the roof of St. Bart’s Hospital. This was the series’ version of the short story “The Final Problem”, in which Sherlock (and Moriarty) also died… only to come back years later (except Moriarty. He’s really dead), and that’s what he did in the series too.
Sherlock season 3 premiere “The Empty Hearse” gave three different theories on how Sherlock survived the fall. The first two were brought by Anderson, who lost his job at the Metropolitan Police’s Forensic Services and became an avid fan of Sherlock and the biggest theorist about how he faked his death. The third theory, however, was given by Sherlock himself to Anderson: Sherlock and Mycroft had everything planned, way before the meeting with Moriarty in St. Bart’s. Mycroft gave Moriarty information on Sherlock, and in return he gave them “hints” so they could measure the extent of his plans. That way, they figured there were 13 likely scenarios once they were up on the roof and planned accordingly, with a codename for each outcome – all Sherlock had to do was send the code to Mycroft.
Everyone around the hospital, including passersby, were there because they had a role in Sherlock’s fake death. He did jump, but landed on an airbag. It was imperative that John stayed exactly where he was so his view would be blocked by the ambulance station. As the airbag was taken out of the way, Molly threw a body dressed as Sherlock through the window. The cyclist that hit John was also part of the plan, as he gave Sherlock time to switch places with the corpse, so John would recognize him. The rest, as he said, was “window dressing”. The final detail, which was also included in many fan theories, was a squash ball under his armpit – with enough pressure, it momentarily cuts off the pulse. As for the snipers ready to kill John, Mrs. Hudson, and Lestrade, they were taken down by Mycroft’s men.
Anderson, like many fans after the episode aired, pointed out that this couldn’t have been possible, and that he was disappointed. Clearly, there are some inconsistencies in Sherlock’s explanation, and fans will never really know if he was telling the truth or not. Series creators Mark Gatiss and Steven Moffat were aware that whatever explanation they gave wouldn’t fully satisfy fans, and read a bunch of theories during the two-year hiatus of the series, which showed in Anderson’s theories and Sherlock’s as well. In the end, fans continue to come up with theories and pointing out mistakes in the final one, making it Sherlock's biggest mystery.