There’s something special about Captain Jack Harkness of the British show Torchwood. Is it that he can’t die and never ages? Is it that he spends his days tracking down aliens with a crack team of ex-cops and specialists? No, it’s probably that Captain Jack is dead sexy, sports an American accent and snogs boys and girls alike.

“It’s wonderful playing the romantic Jack,” says John Barrowman. The actor straddles all kinds of divides; besides being half American and half British, he’s an openly gay man playing one of TV’s most prominent bisexuals. “I get to portray a person on television that I would want to look up to, if I was a kid growing up in America.” Barrowman was also a West End song-and-dance man before becoming a sci-fi alien hunter—he currently judges singing-competition reality shows and is considering a concert series in Las Vegas. “I’d like to be bicoastal,” he puns. Wouldn’t we all? “You can be! You just have to say yes!

Torchwood spun off from the British series Doctor Who in 2006; the latter is a massive television institution in the U.K. The titular Doctor has been played by no fewer than ten actors since 1963 (the 11th takes over in 2010) and is like a nonhuman, time-hopping lovechild of James Bond and Willy Wonka. Barrowman’s Harkness character, clad in his signature paramilitary coat, appeared on the show before getting his own series, this one with a sexy, slightly more adult bent. Now, for its third season, Torchwood is returning with a miniseries called Children of Earth—an entire season crammed into a five-night event.

“Jack is more of a smart aleck with the Doctor,” says Barrowman. “It’s interesting here playing the dark and troubled hero.” And while Harkness gets darker, Barrowman himself will be brighter with BBC America’s new switch to high-definition broadcast. “One of the things about being a guy: Supposedly wrinkles look better on us,” he laughs. Of course, the magical Captain Jack doesn’t age. “We tackle that,” he says. “There’s no way I can stay looking like this for another ten years. There’s not enough Botox on the planet!”

All discussions of beauty aside, Barrowman hopes Children of Earth will be a serious event for the show, one usually known as a kind of cross between Buffy the Vampire Slayer and The X-Files. In the first installment of the miniseries, Harkness and his team respond when every child on Earth is suddenly affected by an alien threat; “The extent of what we’ll go to save our kids…it’s just horrifying,” says Barrowman. And for once, Americans will have to wait only a few weeks after the British premiere to catch the Torchwood miniseries. “As I’m sitting here right now talking to you, millions of families around the U.K. are sitting watching Torchwood,” says Barrowman on the night of the British premiere. But does that freak him out? “Can I be totally honest with you?” he says. “I absolutely love it.… It is the best thing in the world.”—Allison Williams

Torchwood: Children of Earth premieres at 10pm on Mon 20 on BBC America.