Culture Shock 04.15.10: New Doctor makes debut in Saturday's 'Doctor Who'

In Great Britain, the casting of a new lead actor in the long-running science fiction series "Doctor Who" is a monumental event. It's arguably second only to the crowning of a new monarch.

Fortunately, the first episode of Matt Smith's reign should put most fans at ease. The Doctor may be a new man, but his trusty time machine, the TARDIS, remains in good hands.

American viewers can see for themselves when "The Eleventh Hour" kicks off the new season of "Doctor Who," Saturday night at 8 on BBC America. And for newcomers to the series, who may be wondering what all the fuss is about, BBC America will air "Doctor Who: The Ultimate Guide" during the preceding hour.

Simply put, "Doctor Who" is the longest-running sci-fi series on television. It originally aired from 1963 to 1989, when a hostile BBC controller and declining ratings did it in. Then, after a one-off TV movie in 1996, "Doctor Who" finally returned in 2005, with Christopher Eccleston ("Heroes") portraying the 900-year-old Time Lord from the planet Gallifrey.

Eccleston stayed on just one year before regenerating into the Doctor's 10th incarnation, David Tennant ("Harry Potter and the Goblet of Fire").

Over four years and 47 episodes, Tennant redefined the Doctor for a new generation. And by the time he exited the TARDIS for good earlier this year, his incarnation of the Doctor had become the most popular since Tom Baker — the one with the toothy grin, long scarf and floppy hat — owned the role from 1974 to 1981.

Every new Doctor faces some bumps, and Smith is no exception. His tenure was controversial even before he filmed his first scene. At 27, he is the youngest actor to play the part, and he has the bad fortune to follow Tennant.

"The Eleventh Hour" begins with a damaged TARDIS crashing on Earth and the new Doctor still "cooking" after regenerating into his 11.0 version. But from there, Smith quickly finds his footing, and by the end of the episode, there's no doubt that he is the Doctor.

Smith's manic, quirky, yet authoritative performance echoes Doctors past — especially Patrick Troughton and Jon Pertwee — while leaving room for him to find his own voice in episodes to come.

He is aided by his new human traveling companion, Amy Pond (Karen Gillan), a young Scottish woman whose life the Doctor inadvertently turns upside down when he runs into her first as a young girl and then again 12 years later, although only five minutes later from his point of view. Time travel can be a tricky thing.

Smith's tenure also heralds a new executive producer/head writer in charge of the show.

Steven Moffat ("Coupling") takes over from Russell T Davies, the producer who dusted off the show for the 21st century. But while Davies liked to tug heartstrings to the point it became tiresome, Moffat specializes in clever, fast-paced storytelling, with more than a dash of the gothic creepiness that marked the show's high point in the mid-1970s.

Moffat wrote most of the best-received episodes of the Davies era, including "Blink" and the Eccleston two-parter "The Empty Child"/"The Doctor Dances."

With a new Doctor firmly established and the series now under the guidance of its best writer, there is no better time to ask, "Doctor who?"

The answer doesn't disappoint.