The best thing about David Wood's new play for children based on Michelle Magorian's novel is the opportunity to sit once again in the Phoenix Theatre, an art deco temple occupied these last two decades by Willy Russell's Blood Brothers.

It's a plush setting for so simple and sentimental a story, in which an abused London boy - beaten and bullied by his Bible-thumping mother - forms a dependent friendship with curmudgeonly old Tom Oakley in the heart of the Dorset countryside during the last war.

Little William Beech (touchingly played by Ewan Harris at the performance I saw) is a war-time evacuee. His mother has stipulated a religious supervision, but Tom, like Shakespeare's Feste, does live by the church, and not necessarily in it, although he's the caretaker.

Stooping, grumbling and shaking his old white hairs like an ancient sage, Oliver Ford Davies skilfully manages to make Tom - who has lost his own wife and child 40 years previously - vaguely interesting, but it's a close call. His constant companion is a shaggy old dog, manipulated in full view by Elisa De Grey.

Everything Tom says is perfectly sensible and, thanks to William's irruption in his life, he has to negotiate the simple journey of being "Mister Tom" one minute and a loving father the next. There's not so much a fluent narrative as a series of plot points punctuated by bad news in telegrams, or sudden explosions.

Angus Jackson's production - first seen at Chichester - also contains a lot of energetic "child" acting, notably from (at my performance) William Price as the insufferable Zach, the posh village boy who befriends William in between demonstrating the considerable disadvantages of having parents who work in the theatre.

When William returns to the smoke at his mother's insistence, the play suddenly lurches into Edward Bond territory, with an unloved baby, more violence and a scene of social catastrophe in darkest Deptford. Somehow old Tom finds his way to the house, which has opened like a dark cave on Robert Innes Hopkins' otherwise picture postcard design of a Dorset landscape.

Aoife McMahon is charged with playing the maternal harridan but can at least double her with a sunnier character, though not one untouched by tragedy of her own.

We hear Churchill's declaration of war on the radio, and a number of songs popularised by Vera Lynn. And there are some jolly am-dram extracts featuring the children as Toad (and the vicar as Badger) and Peter Pan; which only make you wish you were watching the full-length versions of those stories instead of this one.