“Most people think Sherlock Holmes is real. About 60 percent. And we can’t tell them no,” says Carmen, a Victorian maid at 221B Baker St. “So if someone asks, ‘Does he live here?’ I tend to say yes. Because if you tell them, it’s like breaking their heart.” At the Sherlock Holmes Museum in London, the first ever dedicated to a fictional character, “we often have girls dress up as Benedict, with wigs and all of that. Mainly from Russia? And China!” Josh, the actor costumed as a Victorian policeman, was once made to hold a three-foot Benedict Cumberbatch doll. I ask Josh, “Have you gotten a lot of these — um, Cumberbitches?” (as the enthusiastic fans of Sherlock’s most recent incarnation have labeled themselves). Josh has. They’re hard to miss. “They’re sort of screaming a lot.”

But Emily, another Victorian maid, says the most excited fan was a man in his 80s. “He’d read the books since he was seven. He wasn’t as … animated, but he was in the museum for hours looking over every detail,” she said. For novel lovers, the museum is more than Benedict posters and “I Am Sherlocked” t-shirts. For “Doylebitches,” the game is afoot — hunting instead for clues from every adventure Dr. Watson ever recorded.

Maps gather dust on dull crimson wallpaper. A brass bedstead glints in the light from a gas lamp illuminating Holmes’s chemistry books. On the bed lies a familiar deerstalker hat, left as if the good detective has just strolled into the study — where a parade of teenage girls pout for Instagram, playing with pipes and magnifying glasses. I sit on the couch, assume my best helpless look, and wait for Sherlock to solve my case in his head.

Instead, I meet Dr. Grimesby Roylott upstairs, his head wrapped by a “speckled band” — a malevolent swamp adder. Life-size wax figures of Holmesian villains, just real enough to be unnerving, inhabit the next floor. But selfies ruin the sociopathic chill, as women plant kisses on Professor Moriarty’s cold cheek.

When I ask two elementary-aged boys from Alpedrete, Spain, which is their favorite Sherlock Holmes, the answer is “Iron Man!” A middle school group from Russia responds “everything!” The girls from Taiwan just giggle, “Benedict.”

Sherlock is quite the lady-killer. Letters sent to 221B include “From your woman,” sealed with a lipstick kiss, and “You can run, but you won’t hide! I’ll find you!” from a “PD” in Russia. The museum employees blame it on Benedict. But Sherlock Holmes, Dreamboat Detective, isn’t a new phenomenon. The original 1891 illustrations were based on the artist’s brother, who was then mobbed by the public for the rest of his life.

It’s “Richard the Fourth,” guide of the Holmes in London walking tour, who tells me this. He retells “The Five Orange Pips,” pointing me towards Waterloo Bridge, to imagine a cry and a splash on a dark and stormy night. But it’s easier, watching trains thunder across to the ultra-modern glassy Shard, to recall “The Great Game,” a BBC episode in which five texts warn Sherlock of riddles he must solve to prevent a series of bombings. I’ve wondered if the original detective stories are fading away, lost somewhere behind Benedict Cumberbatch’s billowing trench coat. But Richard attributes the detective’s enduring popularity, the constant pilgrimage of fans to Sherlock’s London, precisely to “the stories’ capacity for constant reinvention.”

Sometimes 1891’s grit clamors through to 2014. We funnel into an alleyway leading to the Nell Gwynne, a pub giving off indiscriminate food-and-alcohol-and-muddy-brick smells, jostling uncomfortably until I can imagine Holmes, disguised as a sooty beggar, crouching with us, eavesdropping on the carriages of the Victorian Strand.
The tour ends at a pub, once the Northumberland Arms, where Henry Baskerville stays in the novel, The Hound of the Baskervilles, but known since 1957 as the Sherlock Holmes. An immense bust of the Hound droops over the bar, next to handcuffs “used by Scotland Yard.” Watson’s Wallop ale flows. Through modern London — a haze of mass-produced pipes and hats and magnifying glasses — even through Benedict Cumberbatch’s cheekbones, Sherlock survives. If the Reichenbach fall didn’t kill him, time could never do the job.

I ask a fellow tourist, “How do you like the pub?” He responds, “Where’s my pipe?”