While “Downton Abbey” is seemingly the most successful British import since the Beatles, other shows from the U.K. are enjoying their share of Stateside success.

Foremost among these is Emmy-nominated miniseries “Sherlock,” the ultra-modern update of Arthur Conan Doyle’s iconic investigator, created by “Doctor Who” scribes Steven Moffat and Mark Gatiss. Though not quite the water-cooler staple “Downton” is, the PBS “Masterpiece” detective drama has garnered critical acclaim — and some of the highest ratings in public television history — by steadfastly refusing to dumb down its material.

Unlike the regrettable pair of Guy Ritchie-helmed Sherlock Holmes films, which share little more than a title with Conan Doyle’s stories, the Moffat and Gatiss version is a love letter to the source material, staying true to the original text in every way that matters while still oozing modernity. Their Sherlock is a habitual texter who uses gadgetry like iPhones and GPS to solve crimes, all while Dr. Watson chronicles the pair’s adventures on a blog.

“One of the features of the original stories is that he wasn’t a period piece character; he wasn’t a fussy old uncle,” Moffat says of Holmes. “He was a young man and he was a scientist who was up-to-the-minute on forensics … cutting-edge and modern.”

That modernity is enhanced by the casting of Benedict Cumberbatch (“Atonement”), who embodies Holmes so completely that he was the only actor ever considered for the role.

“I look weird,” Cumberbatch says. “I look like I’m slightly of another era, but I’m obviously in the 21st century, so I kind of fit the bill of being slightly Victorian in a weird way.”

Cumberbatch’s Holmes is selfish, arrogant and socially inept, yet charming and witty enough to win over audiences. He’s a man of smoldering intelligence whose rapid-fire dialogue is delivered at a breakneck pace, forcing the viewer to pay close attention or else get lost in the twists and turns of the story.

“The amount of detail, the amount of plot that can be contained in one moment of him diatribing about a crime scene, is a thrilling bit of theater, really,” Cumberbatch says. “His thought process is like a stream of consciousness.”

For all its verbal alacrity, “Sherlock” also has a distinct visual style developed by Paul McGuigan, who has directed two-thirds of the episodes. Much of the plot exposition is delivered via text messages, which appear not in cutaway insert shots, but instead float and dance across the screen in visually arresting subtitles.

Holmes’ own internal thoughts frequently appear as subtitles too. It’s a lot for viewers to keep up with, but both Moffat and Cumberbatch say challenging the audience intellectually is what sets the show apart from the usual primetime fare.

“It doesn’t matter if you don’t get every single bit of all of his deductions. Who ever does?” Cumberbatch says. “I think people like not being insulted, I really do. We’ve gotten far more sophisticated as audiences because we see media in such different ways, and yet still in our mainstream output on television it’s all about people being patronized.”

With each 90-minute episode based on a different Conan Doyle tale, Moffat and Gatiss are busy working on scripts for the third season, which begins filming in January. In the meantime, the cast and filmmakers are reveling in the unexpected buzz.

“None of us had any idea it would become this sort of phenomenon,” Cumberbatch says. “We’re just touched and delighted about the whole thing. It’s certainly taken us by surprise.”