In the time between the death of Sherlock Holmes in Arthur Conan Doyle’s 1893 short story “The Final Problem” and his resurrection in 1903, fans theorized about how he survived. This was the birth of fan fiction (or fanfic). Year zero.

In 2012, when BBC’s Sherlock television series ended its second season in a similar fashion, fans took it upon themselves to pick up the pen once again (rather, keyboard). This is the era of the fanfic renaissance, wherein Sherlock Holmes and sidekick John Watson can be partners — both professional and romantic.

Ask any member of the fanfiction.net Sherlock community if they desire more, ahem, situations between the titular characters and one might be surprised: There are more promoters of a serious romantic relationship between the BBC version of Sherlock and Watson than there are stars in the universe.

Season three of the hit British series Sherlock began in January on PBS with “The Empty Hearse,” and within the first episode a wink and a nod to that subset of the fandom when Holmes (Benedict Cumberbatch) and villain Moriarty (Andrew Scott) came dangerously close to a smooch. After the second season’s cliffhanger ending, reminiscent of the fall that Doyle had hoped would kill Holmes in the original short story, fans began to write. Whether locked in romance or hounding for adventure, new stories for John Watson (Martin Freeman) and Holmes appeared, all separate from the world that creators Steven Moffat and Mark Gatiss envisioned.

Moffat and Gatiss must have been well aware of the world developing online; many fan-theorized ideas make their way into season three.

A conspiracy theorist and the Sherlock Holmes Fan Club represent the overzealous fan base in episode one, throwing out ideas and potential explanations as to how Holmes survived the fall. Of the multiple retellings of the event, from using bungee cords to inflatable bags and even a hypnotist, which one is true? Perhaps all or none. Moffat, who is no stranger to toying with his audience from his experience as the showrunner for Doctor Who, realizes that whatever the explanation, it could never satisfy the diehard fans.

Holmes at one point explains in detail how he did it, and yet we, portrayed by the theorist, refuse to believe him. So there is no official explanation or there are many, whichever you prefer.

The relationship between Watson and Holmes is explored more deeply than ever. In episode two, “The Sign of Three,” Holmes is almost unrecognizable. His cold and calculating persona has dematerialized and in its place a kind, if socially awkward, friend who tries.

Season three exudes happiness; even the villains seem casual. Perhaps this is the reason why fans became very uneasy after episode two. Nothing in a Moffat universe remains pleasant for long.

Season three of Sherlock is constructed from “what-if” scenarios that Moffat and Gatiss undoubtedly pieced together from their own fandom. After all, Sherlock Holmes is a character written by fans and for fans since the 1800s, for which finality is a non-factor. For the casual viewer, this could be a blessing or a curse, but in the end it’s what ultimately makes Sherlock special.

The Sherlock Season 3 finale, “His Last Vow,” airs Sunday, Feb. 2, at 10 p.m. on PBS.