Introducing a new Doctor is always something of a gamble in the “Doctor Who” universe, but producers have made a savvy choice in Peter Capaldi as the 12th incarnation of the iconic time (and space) traveler. Already a seasoned pro and recognizable smallscreen star in the U.K. thanks to Armando Iannucci’s “The Thick of It,” Capaldi couldn’t be more different from the star-is-born discovery of predecessor Matt Smith, rendering comparisons between the two futile at best. This strategic about-face proves its worth in the season premiere — titled “Deep Breath” and written by showrunner Steven Moffat — especially in the immediate rapport Capaldi strikes with sparkling cast holdover Jenna Coleman. Fans shouldn’t fret, the TARDIS remains in good hands.

As risky as it sounds to swap out a lead actor on a successful series, the built-in reset button isn’t just a part of “Doctor Who” mythology (the character can “regenerate” when his current form sustains a mortal injury), it has emerged as the key to keeping the BBC franchise continuing for more than five decades. Exempting a 15-year hiatus that spanned all of the ’90s (an attempted American revival via a backdoor pilot at Fox in 1996 fizzled), “Who” just keeps going and going. Capaldi is now the fourth actor to lead the show in the past decade alone.

Still a mega-hit across the Pond, the current run has cultivated a growing fanbase in the U.S., boosting BBC America to multiple ratings highs in recent years. One modest concern Stateside may be what those relative newcomers make of Capaldi, especially given that he’s the oldest actor ever to take on the role (at 56, he has a year on the original Doctor, William Hartnell) following the youngest (Smith).

It shouldn’t really be an issue. What Capaldi lacks in youthful energy, he more than makes up for in gravitas and wry eccentricity, whether marveling at his “independently cross” eyebrows or gleefully embracing his Scottish accent as a license to complain. And, since being fiftysomething isn’t what it used to be, Capaldi eagerly throws himself into the action, confirming his Doctor won’t miss a beat when it comes to a smashing fight or chase sequence.

As if to underscore the point, “Doctor Who” proves plenty frisky itself in the wake of its own 50th anniversary last year. After years of speculation, the Doctor unceremoniously outs himself as an atheist in the premiere, though a creepy epilogue suggests the reveal is part of a larger arc for the season.

That provocative nugget aside, Moffat’s script emphasizes storyline continuity and easing faithful viewers into the regeneration transition (if you’ve never seen an episode, it’s probably not the best entry point). The narrative wisely pivots on the Doctor’s companion, Clara (Coleman), struggling with whether or not this seemingly new man truly is the same person she’s grown to love on their adventures together.

Consequently, the plot runs secondary to the emotional throughline here, but its melange of robots, spontaneous combustion and a dinosaur in Victorian London provides ample opportunity for meta references to transformation and evolution.

Feature helmer Ben Wheatley (“Kill List”) establishes an eerily menacing atmosphere for the robo-adversaries (even if the conceit of characters holding their breath to escape detection feels derivative of another Moffat creation: the “Don’t blink” defense against recurring villains the Weeping Angels).

Everyone involved can take particular pride in the centerpiece restaurant tiff between Clara and the Doctor, which cements their new relationship and showcases the instant chemistry between Coleman and Capaldi — built on the ability to push each other’s buttons rather than underlying sexual tension. (Clara will get her own age-appropriate love interest in a subsequent installment.)

Fittingly, “Deep Breath” opens and closes with tributes to bygone Doctors. The first plays strictly for laughs as recurring comic-relief character Strax (Dan Starkey) delivers a condensed (and slightly repetitive) regeneration timeline in the style of a roast. By the kicker, the mood has shifted to a more sentimental and highly effective passing of the figurative baton.

It’s a skillful tonal balance that defines the best of “Doctor Who,” and exemplifies the ethos that keeps the series going strong, nodding to the past with all eyes on the future.

TV Review: ‘Doctor Who,’ Season 8

(Series; BBC America, Sat. Aug. 23, 8:15 p.m.)

  • Production: Filmed in the U.K. by BBC Wales for BBC One.
  • Crew: Executive producers, Steven Moffat, Brian Minchin; producer, Nikki Wilson; line producer, Tracie Simpson; director, Ben Wheatley; writer, Moffat; camera, Magni Agustsson; production designer, Michael Pickwoad; editor, Will Oswald; music, Murray Gold; casting, Andy Pryor. 105 MIN.
  • Cast: With: Peter Capaldi, Jenna Coleman, Neve McIntosh, Catrin Stewart, Dan Starkey.