Playing twins in family drama, The Spiderwick Chronicles, was the ideal challenge for young Freddie Highmore, he tells Steve Pratt

YOUNG British actor Freddie Highmore is only 15 but has already amassed an impressive list of big screen co-stars C Kate Winslet, Dustin Hoffman, Russell Crowe, Robin Williams, Kenneth Branagh and Johnny Depp twice.

The Spiderwick Chronicles, based on the best-selling books, gives him not just his first leading role, but two leading roles as he plays twins, Jared and Simon.

Together with their mom and sister Mallory, they move from New York into the secluded old house owned by great-great-uncle Arthur Spiderwick. When strange things begin to happen, the youngsters investigate and are plunged into a dangerous world of creatures only they can see.

The book was bigger in the US than over here when he first auditioned for the roles, Highmore recalls. In a screen test in America, they tried out the whole twins thing.

It was a great opportunity to play the twins and have two characters, it was fantastic, he says. It was something I was looking forward to and its important to do new things with each film and have challenges.

This was something Id never done before.

Originally, they were trying to get real twins to do it and I think logistically that would have been easier. We wanted to see if it would work out technically if I played them both.

The need to film many scenes twice C once with him as Jared, then again as Simon C made for a fourmonth plus shoot in Canada. The twins are visually and vocally different. We tried to get quick changes done. We needed to know which twin was which, he says. We got down to a Ferrari pit stop time in the end. Id go into the tent, change and come out as the other character.

When they were in the same shot, we had to rehearse a long time and still sometimes it went wrong and it would look like I was walking into myself.

It was a matter of working out everything in advance to show how the twins had grown apart.

Genetically theyre the same person, so it was how different changes had affected them during their lives, made them grow apart and react to different situations, says Highmore, whose past films include Finding Neverland and Charlie And The Chocolate Factory.

It was also important to keep Simon in the film as he could easily get lost because Jared is more prominent and the louder character, he adds.

The parts also offered the experience of acting opposite a collection of CGI creatures C including goblins and trolls C created by the special effects people after hed filmed his scenes. You knew what to expect a little bit and find youre acting to a blue ping pong ball or something like that and pretend theyre these giant creatures, he says.

They made it easier by showing us animations and had the voices recorded beforehand so they could play them over a loudspeaker. We had something to react to and it wasnt going at it without any knowledge.

He also had to grapple with these imaginary creatures. When Simon gets tripped up and taken off into the forest by the goblins, they attached things to my body and there were various men dressed in black, who obviously got edited out, dragging me along and running off into the woods.

We tried to do it a bit realistically so it wasnt just me lying there wriggling around. There was someone actually moving me along.

Hed done an American accent in his first movie, August Rush, so it was going back to that rather than learning a new one for The Spiderwick Chronicles. There was a coach on the set, but he also spent most of his time talking in an American accent so it became second nature to him. He made things more difficult for himself by differentiating the twins vocally.

Time spent filming in Montreal was useful as he was able to practise his French. He may be an accomplished screen star, but has to take exams like any other teenager.

When hes not filming, he goes to what he calls normal school in London. While away, he has a tutor and contact with his school.

Its like being in school, but in another world. I still think Im a normal guy really, says Highmore.

I know its funny. I say Im a normal lad as its not normal to fly around the world making movies.

My friends are always interested in what youre doing, but I talk more about other things C like how Arsenal is getting on.

As to whether acting is a career for life, he remains undecided. Im really happy doing it. Its been an amazing opportunity and great experience. If it continues like this, then yes Id like to carry on doing it.

Its also important to keep your options open, do exams and university. You might wake up one day and think I want to do medicine.

Im sensible in that way, he says.

Having acted twice with Depp, he must have had some influence on young Freddie. Hes a top guy, very down to earth and normal and talks to everyone in the same way.

Highmore seems to be following his good example as one of the most unspoilt young actors around.

ö The Spiderwick Chronicles (PG) opens in cinemas tomorrow.