The time-traveling, alien lead character in “Doctor Who,” aptly enough, has stayed young.

Since it started airing in 1963, the BBC show has fought off old age and dwindling attention spans of the men playing the titular lead with a clever concept: Whenever the Doctor dies, he regenerates into a new body. He retains essentially all the memories of his past selves, but his appearance, his accent, even his personality, can be vastly different.

As a result, “Doctor Who” has been able to run for 50 years with 12 actors taking the lead—quite a feat of longevity.

You can make it 13 now, following the eighth season premiere of the 2005-relaunched “Doctor Who” series. After Matt Smith stepped down from the role with last year’s “The Time of the Doctor” Christmas special, now comes Peter Capaldi full-time, following two quick cameos in the aforementioned special, and prior to that, the 50th anniversary episode, “The Day of the Doctor.”

Casting of Capaldi

Let’s get one thing straight about Capaldi. He’s old. The Scotsman is a ripe 58, taking over for Smith, who was only 26 when he got the role in 2009. Smith was preceded by David Tennant, 34, when he became the Doctor, while Christopher Eccleston was 41 for the sole year he spent piloting the time machine called the TARDIS (time and relative dimensions in space).

In other words, the casting of Capaldi snaps a streak of younger and younger actors playing the Doctor, going in the complete opposite direction on the timeline.

Appropriately enough, the episode “Deep Breath” starts with a dinosaur roaming around Victorian London. Haha, not Capaldi, but a huge Godzilla-sized T-Rex, which resists the temptation to smash Big Ben.

Casting “Doctor Who” has always been a big deal, especially since the show really took off with its second run nine years ago. “Who will be the next Doctor Who?” is something you can bet on in the UK.

There was plenty of hand-wringing when Smith got the job because of his youth and he was a relatively unknown actor. Capaldi, though, is the opposite. He’s a veteran actor. And yet Whovians were openly skeptical about him.

Part of the modern show’s appeal was the “ship-ability” (from the word “relationship”) of the Doctor and his gorgeous female companions, a.k.a. the ability of a segment of fans to imagine or predict a romance brewing between the two characters. However, the age gap between Capaldi and his co-star, 28-year-old Jenna Coleman, who plays 27-year-old Clara Oswald, made it rather dicey.

So, why age the Doctor in the first place (and potentially alienate fans)? It’s a question the characters themselves try to grapple with, resulting in more than a few meta-lines of dialogue. Though Clara was by the Doctor’s side when the 11th Doctor (Smith) regenerates into the 12th (Capaldi), she’s initially convinced the two are not the same person, and that there must be a way to bring back 11.

There’s a scene where Clara is confronted by a friend of the Doctor, Madam Vastra, who hints at having seen multiple incarnations of the Doctor. Speaking as much to the audience as she is to Clara, Vastra points out, “You thought he was young? He is the Doctor. He has walked this universe for centuries untold. You might as well flirt with a mountain range.”

When Clara asks what reason he would have for looking young, Vastra answers, “The oldest reason there is for anything. To be accepted.”

Real villain

But there also appears to be plot-related reasons for the Doctor being old. In a fit, he rants, “Why did I choose this face? It’s like I’m trying to tell myself something. Like I’m trying to make a point. But what is so important I can’t just tell myself what I’m thinking?”

The episode doesn’t really start to hum however, until the Doctor and Clara encounter the episode’s real villain. In a throwback to an early David Tennant episode, our heroes try to thwart a cyborg that has been harvesting human organs using a restaurant as a front (like “Sweeny Todd without the pies”), in an effort to keep itself functional and repair his ship enough to reach “the promised land.” Clara and the Doctor are crackling in their scenes together, but we also begin to see the differences in 11 and 12’s personalities.

No longer a swashbuckling pulp hero who yells “Geronimo!”, there’s more menace to Capaldi’s Doctor. After pouring the cyborg some whiskey, Capaldi’s delivery of the line, “I’ve got a horrible feeling I’m going to have to kill you. I thought you might appreciate a drink first,” is chilling, almost movie villain-esque, ironically.

It gives a later monologue, where he compares the body-part harvesting cyborg to a broom that’s had its handle and brush replaced so much that it’s not the same broom anymore, added poignancy. It’s a statement that can apply to himself as well, because of all his regenerations.

It’s hard to judge a  new actor playing the old role in just the first episode. Storywise, the trauma of regeneration has the Doctor freaking out, as he come to grips with the end of an old life and the coming of a brand new one.

While the relationship between Doctor and companion may no longer be as “flirty” as it was in the past, that the two still banter enjoyably back and forth can only mean good things for the series, tempered however by rumors that Coleman may be out after this year’s Christmas special.

Near the end of the episode, the Doctor, pleading to Clara to stay with him as his companion, says, “I’m right here. Standing in front of you. Please, just see me!”

Despite the gruffer, weathered, and yes, older exterior, we do see you Doctor, and we’ll continue to do so in this new run.