Sharon Stone is a US vice president with a powerful secret in the new TV thriller Agent X

Stone's character stumbles upon a hidden passage in the US Constitution that gives her super-secret powers.

Sharon Stone as Natalie Maccabee and Jeff Hephner as John Case in Agent X. James Dittiger / TNT

Having a job that is a heartbeat away from the Oval Office hot seat would be enough to give most people ­palpitations.

But discovering that you are also above the law – with your very own secret agent to set on baddies around the world – brings a thrilling new dimension to the role of Vice President of the United States.

Such is the premise of Agent X – a new action series that begins on Saturday on OSN First HD – which stars Sharon Stone as Natalie Maccabee who, shortly after taking up her new job as US vice president, discovers a hidden passage in the US Constitution that gives her super-secret powers.

Not even the president knows his VP has a hush-hush mission to tackle threats, foreign and domestic, and the ability to freely operate with “judicious disregard for accepted legal formalities”. Why is the commander in chief kept in the dark? To give him “plausible deniability” if things go wrong, of course.

A Golden Globe winner and Oscar nominee for her compelling turn as a mob wife opposite Robert De Niro in Casino (1995), Stone also has an Emmy to her credit for her guest-star role on TV drama The Practice. Also an executive producer on Agent X, the ever-provocative, and well-toned Stone – who turned 58 in March – raised eyebrows last September when she posed for Harper's Bazaar wearing nothing but high heels. So what possessed the silver- screen seductress to take on a much more family-friendly role?

“Well, I’ve been looking to do a series,” she says. “My kids [sons Quinn, Laird and Roan] are still little – they’re 9, 10 and 15. I wanted to be a stay-at-home mum, and do a show in town.

“We’re very lucky. We get to shoot in Los Angeles, which is heaven. I get to drive to work, 15 minutes down the street. I mean, c’mon, this is awesome.”

While Stone is happy to be working close to home, the global scope of the series “allows us to see the kinds of things that are happening in the news and around the world now – but in a way that families can talk about it,” she says. “And then I, as the vice president, get to have a secret agent – and who doesn’t want to do that?”

Maccabee's licensed-to-kill right-hand man – you could call him a "Yankee James Bond" – is buff, tough and witty John Case, played with bravado by Jeff Hephner, an actor best known for his work on The OC and Easy Money.

As her Agent X, he gets to handle the sensitive cases that fall beyond the purview of the CIA and the FBI.

Also in the mix is veteran character actor Gerald McRaney (Deadwood, Jericho, Major Dad) as the fiercely patriotic Malcolm Millar, chief steward of the vice president's mansion. Just as Batman has his Alfred, every hero needs a stodgy but capable ­butler-like character to batten down the hatches on the home front and spin some comic relief – and Millar is a dab hand at tackling not only global threats, but also the political intrigue of Washington, DC.

“Obviously we’re building a mythology – and [current US vice president] Joe Biden’s not in charge of any agents that I know of out there,” says Hephner. “It’s also hilarious when you tell people, ‘well, my boss is Sharon Stone’.”

Recalling his days as a star-struck teenager watching Stone in sci-fi epic Total Recall (1990) and controversial thriller Basic Instinct (1992), Hephner says it took him a while to get over the fact that this one-time Hollywood phenomenon is now his acting partner in Agent X. But they easily formed a bond.

“We, early on, had to do a scene where we were in a car and once they put the cameras around the doors, you’re locked in for four hours,” he says. “We talked about kids, and life, you know, where you’re going to put your kids in school. Halloween. Really normal stuff.”

The athletic Hephner, 40, also does as many of his own stunts as possible, which can be physically punishing in such a high-octane series.

“It’s ridiculous, but I haven’t had this opportunity to be this ‘action guy’ before,” he says. “And in TV, you never know how long it’s going to last. It could all go away. If you don’t watch this, I could be back making pancakes. So I wanted to do it all – and you put yourself in harm’s way a lot.

“And it’s bizarre: you think about it and how much fun it is – but then I go home and I’m just beat up. I fly home to Michigan every weekend, and my wife will be like: ‘What are they doing to you?’”

Agent X begins at 11pm on Saturday, May 21 on OSN First HD