The much-loved children's book Goodnight Mister Tom is 30 years old this year – and a play based on the classic tale of a wartime evacuee and a reclusive old man who strike up a remarkable friendship is visiting the Theatre Royal. EMMA LEE dropped in on rehearsals.

It's a grey chilly day at the end of January — one of those days when the weather can't make up its mind if it's still the depths of winter or there's a hint of spring in the air.

In a church hall in north London a group of actors is locked in rehearsals for a new stage production of the much-loved wartime tale, Goodnight Mister Tom.

A choir of young voices reverberates spookily round the rafters as they launch in to a rendition of Wish Me Luck As You Wave Me Goodbye.

It's been an intense four weeks for the cast and crew as they bring the story from page to stage.

The play is at Norwich Theatre Royal next week. It has been adapted from Michelle Magorian's book, which is 30 years old this year, by National Children's Dramatist David Wood and is directed by Angus Jackson, associate director at Chichester Festival Theatre.

It's the first production under the umbrella of the new Children's Touring Partnership which aims to take imaginative and bold high-quality theatre on tour which appeals to children aged eight and above.

Going Out was invited to Islington to meet some of the actors, and, excitingly, have a sneak preview of the production.

The set and costumes might be missing, but it's still a gripping piece from the off.

It's the story of gruff loner Tom Oakley and youngster William Beech.

The pair's lives collide when William is evacuated from the city to the countryside as the country is on the brink of war.

They are both complex characters who wear their own personal battle scars. But the pair strike up a remarkable friendship.

All goes well until William is summoned back to London and their bond faces an incredible strain.

The cast performs the first scene, in which Tom, played by renowned stage and screen actor Oliver Ford Davies, and William, who is played by a trio of young actors who take turns in the role, are introduced, especially for Going Out.

Another important character is Tom's faithful border collie, Sammy, who helps William to come out of his shell.

In this production, Sammy is a puppet, expertly operated by Laura Cubitt.

Laura, who has worked on the show War Horse, really brings the dog to life – the movements are so astonishingly authentic that after a few minutes you almost forget he isn't real and she blends into the background.

Oliver's CV includes the part of Sio Bibble in the three Star Wars prequel movies, Polonius opposite David Tennant in the RSC's production of Hamlet and several series of Kavanagh QC opposite John Thaw, who starred in the Bafta award-winning TV version of Goodnight Mister Tom.

He also knows Norfolk well. He has relatives in the county and worked on several Anglia TV productions, including Rattigan's Cause Celebre with Helen Mirren and David Suchet.

Oliver says that he is enjoying playing such an interesting, multi-layered character.

'It's a very good part,' he says. 'These two have been thrown together arbitrarily and against their will. They make a very odd couple.

'We keep Tom gruff and distant as long as we can until he begins to bloom. But he performs acts of kindness without realising it – he will offer to read William a book and he does it without having thought about it.'

Oliver has nothing but praise for his young co-stars.

'They are very professional and very focused. They're very quick to pick things up – yesterday they were given some new lines and they were straight in. A lot of them have come straight out of Les Miserables and Oliver. Young actors are in demand – we were lucky to get them,' he says.

And they deal well with the complexity of the bruised little character.

'It's interesting to act with three different kids because they're all quite distinct.

'I think children have a very intuitive grasp of things you ask of them – they just do it. And they're very quick emotionally,' Oliver adds.

Puppeteer Laura's role is incredibly physically demanding. Border collies are energetic dogs, and even when Sammy isn't bounding around the stage and is resting, Laura mimics his breathing to make him as realistic as possible.

Laura, who has family and friends in Norfolk, trained as an actress, but has found that puppetry skills are becoming more and more in demand in live theatre.

'I suppose I start by looking at how the puppet moves – we had a prototype from the first day of rehearsals, then the actual puppet came.

'It's a beautiful thing.

'In my mind there's a meeting of the puppet's movement and then trying to embody the energy and essence of the dog.

'I think [William's arrival] is incredibly exciting for Sammy. I don't think there have been that many visitors. I think Sammy senses William's vulnerability,' she says.

'There's definitely a stamina to build up. My body's getting used to being bent double!'

t Goodnight Mister Tom is at Norwich Theatre Royal from March 9-12, �16.50-�5.50, 01603 630000, www.theatreroyalnorwich.co.uk