Jenna-Louise Coleman and Matt Smith Jenna-Louise Coleman and Matt Smith

The Doctor's search for his elusive (and twice-dead) companion Clara has come to an end.

On Saturday, Doctor Who returns at 8/7c on BBC America for the first episode with Clara Oswin Oswald (Jenna-Louise Coleman) in her official capacity as companion to the Doctor (Matt Smith). We previously met her as the futuristic hacker Oswin ("Asylum of the Daleks") and Victorian governess Clara ("The Snowmen"), but those run-ins merely set up the mystery of the woman who was destined to travel with the Time Lord. Now he's found her in contemporary London.

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"They're different and from different time periods, but there's a similar essence and spirit throughout them," Coleman tells "Our Clara has grown up and is born and raised in contemporary London, so her lifestyle is very different from Oswin who's been locked up on her own for a year and has kind of gone mad and is not as feisty as the Christmas Clara. This Clara doesn't wear her heart on her sleeve. She has quite a lot of secrets."

Despite that reserved nature, Clara is willing to take a gamble on this funny man in tweed and a bow tie. "She's always wanted to travel and explore the world. She's got a book called The 101 Places to Go that was given to her by her mother," Coleman explains. "She's in that stage of her life where she's finished university and she's floating around. She doesn't know what she wants to do with her life. She just knows that she wants something kind of more. This is when the Doctor comes into her life and offers her all of time and space."

That adventurous spirit leads her to enter the time-travel spacecraft the TARDIS with a man who tells her, "I'm the Doctor. I'm an alien from outer space, I'm 1000 years old, I've got two hearts and I can't fly planes." Check out the clip below to see their strange introduction:

After that rollicking start, the pair zip around London. "We had to go and shoot in London for a couple of days and ride on the back of a motorcycle and go around the Houses of Parliament and Big Ben. I felt incredibly British that day," says Coleman.  "We were both on the back of the bike, but when I had read it in the script, I had imagined me clinging onto the Doctor, the wind blowing in my hair and all that action. You get to set, and obviously being Doctor Who, you get these comedy goggles and this funny hat. And Matt's so tall that I can't see over his shoulder, so I'm totally not looking like the sexy James Bond girl whatsoever."

In this London, the ubiquity of wi-fi is actually quite dangerous. Guest star Celia Imrie (Bridget Jones's Diary) plays Miss Kizlet, the episode's villain. "She's running what is kind of the iCloud. It's the wi-fi that sucks people up into the iCloud," Coleman says. "It's kind of like being sucked into your computer and your iPad. People keep vanishing and disappearing."

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Of course merely having your entire being uploaded isn't scary enough for Doctor Who. The people are uploaded by a new type of monster that executive producer and writer Steven Moffat calls the Spoonheads. "You can basically see their face, and it revolves around and it's a Spoonhead. You can see their reflection and it's pretty scary," Coleman says. "I seriously don't know what goes on in Steven Moffat's genius to come up with these things.

"The funny thing is that obviously shooting it, you don't see anything because it's all CGI," she adds. "It almost is quite funny because whoever is a Spoonhead, they just have a green cap stuck on the back of their head. And they get put on this spinny-like turntable. And there's a guy on the floor spinning them."

Check out this clip of Miss Kizlet, and check back next week to learn more about Coleman and the mystery surrounding Clara.

Are you glad the Doctor is back with Clara in tow? Doctor Who airs Saturdays at 8/7c on BBC America.