Henry Ian Cusick is experiencing a big-in-Japan moment. Just weeks ago, the actor couldn’t leave his LA apartment without being mobbed by squealing fans, but back home in Britain nobody has a clue who he is.

All that will change next year, when the second series of Lost, the hit American desert-island drama, is aired in the UK. Cusick joins the cast at the start of series two (currently airing in America), playing Desmond, an enigmatic Scot who appears to have been hiding out on the island since before the plane crashed, leaving 48 telegenic survivors stranded.

His star status will be further enhanced next year with a big screen appearance opposite Demi Moore in the film Half Light.

“It’s strange,” reflects the half-Scots, half-Peruvian actor, sitting in the living room of his Kent home, surrounded by books and videos as well as children’s toys, a punchbag and an accordion. “One minute people are coming up to you at the supermarket checkout and the next you are back home and it is as if it never happened.”

Home is a three-bedroom house in Shipbourne, a village located between Sevenoaks and Tunbridge Wells. It has a church, a school and one pub. The only time Cusick makes the 40-minute journey to London is for auditions.

The 36-year-old actor seems bewildered by the sudden upturn in his career. Back in August he was spending a quiet day at home when he got a call out of the blue from his agent in LA asking him to audition for an American television series he had never seen.

He obliged and within a week was sitting on a plane to Hawaii, a newly signed member of the cast of the Emmy-award-winning show. “There are so many strands to Lost and so many characters and I think that’s what makes it so appealing. It is about faith, religion, action, sci-fi, soap, a plane crash — it’s not just a cop show or a medical show, so it appeals to everyone,” he says in an accent that owes more to the 18 years he spent in Scotland than to his childhood in Trinidad and Tobago, Peru and Spain.

Cusick is reluctant to say anything about his character, Desmond, for fear of spoiling this series for viewers and he won’t be drawn on the rumours that he is one of the bad guys. In a plot twist it emerges that Desmond has already had a past encounter with one of the crash survivors, who play out their own intense personal dramas while the rest of the world is oblivious to their existence.

From the outset the producers of Lost had their eye fixed on the slot occupied by Sex and the City and then Desperate Housewives as the show everyone was talking about. The first episode cost $12m to create, making it the most expensive pilot in television history. Series one reached an impressive audience of 20m in America.

Originally intended as a one-off series, the programme’s popularity forced the producers to get to work immediately on a second series. “Everyone keeps telling me how exciting it is and I’m delighted to have got the role, it’s an incredible thing to be part of. But it doesn’t feel real because my life really hasn’t changed that much,” he says.

Channel 4 might not take series two, he argues, and nobody in Britain might ever know the name Henry Ian Cusick. Given that Channel 4 spent an unprecedented £1m marketing Lost and that 6.4m viewers tune in every week, this seems extremely unlikely.

Cusick, though, is superstitious. Keen to emphasise the normality of his existence, he lists his engagements for this afternoon — collecting his three sons from school and taking them to karate, going to the supermarket and getting dinner ready for when his wife, Annie Wood, comes home.

“My whole life is very relaxed,” says the actor. “My wife works full time, so when I don’t have a job on I’m at home with the kids. It works pretty well.”

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