{alltv} 'Torchwood' star Eve Myles: Gwen and Jack are 'two missing parts of a jigsaw'

There's a moment in the premiere of "Torchwood: Miracle Day" -- which you've quite likely seen in the previews -- when Gwen Cooper (Eve Myles) pops earmuffs on her baby girl so she can fire off rounds at a moving helicopter.

It isn't the first you see of the character in the new season, which has been dormant since "Children of Earth" aired in 2009, but it's the perfect reintroduction. She's the same as ever, but her priorities have noticeably shifted to accommodate the changes in her life.

"You find Gwen living in almost complete isolation," Myles recently told Zap2it when we met with her on the set of the series. "It's almost like a chocolate box cottage. It's like the perfect cottage somewhere in the UK, and she's hiding from the CIA because she's the only Torchwood member left. She's a hunted woman. You see Gwen like you've never seen her before. She's constantly on alert and living in fear."

But the events of the "Miracle" (the end of all human deaths on the planet) quickly force her out of hiding and back into her partnership with Jack Harkness (John Barrowman), who she's been estranged from for years.

"What Gwen doesn't know is that Jack has never left her," she says. "Jack turns into Gwen's guardian angel and watches over her and keeps her safe at all times -- hence, episode 1, why they come back together. He can't keep her safe, so he has to come back."

Despite their time apart, both on camera and off, nothing has been lost in the alternatively warm and snarky partnership between Gwen and Jack -- and Myles and Barrowman. The duo's chemistry has only benefited from the time off.

"They have an extraordinary relationship," says Myles. "They have a love-hate-love relationship, they have a brother and sister relationship. They have husband and wife relationship. They have the best friendship known to mankind. They're the two missing parts of a jigsaw, and when you find them, they'll always be together. It's a sensational soul-mate relationship, and there's no label for it."

She's equally affectionate about her own relationship with Barrowman. "John is my oldest and dearest friend," she says. "Strangely enough, we've never had a falling out. We complement each other, we have so much respect for each other, and we adore each other."

Working with Barrowman again is just one of the many highlights Myles found on "Miracle Day."

When "Children of Earth" aired in the summer of 2009, despite winning the series' strongest reviews to date, it was very much up in the air as to whether or not we'd see more from the "Doctor Who" spin-off. All but three members of the original cast had been killed off, and budget often becomes too much of a hindrance in the genre.

Myles was 7 months pregnant with her own daughter Mathilde (now 19 months old) when she got the word that Starz and BBC would co-produce the series for a 10-episode arc. "It was one of those phone calls everybody hopes to get," she says. "And it's been incredible. Literally, from day one, it's been the most exciting time of my life. Coming to work at the Warner Brothers lot every day is my dream come true. I'm ecstatic."

Seeing the finished product has also been a high point for Myles. We spoke with her just after she screened the first episode. "I'm Gwen Cooper and I'm blown away by it. I'm really excited. I can't wait for people to see it."

And its not just the special effects and considerably larger budget that has her confident its the series' best offering to date. "It doesn't make the story gross and it's not over indulgent," she assures us. "It's just that we have the effects that we've always wanted. We've put so much hard work into the series since the begin, it seems like we've been given a gift in [Season] 4. We've been given a treat. We're telling a brilliant story. And on top of that, aesthetically, it's beautiful and it's wildly big. It's movie big."

See Eve Myles step back into Gwen Cooper's shoes when "Torchwood: Miracle Day" premieres on Starz, Friday, July 8, at 10:00 p.m. ET.