�There is a kind of children�s book which is rare, but which includes some of the very best literature for the young. The Silver Sword, Goodnight Mr Tom, The Butterfly Lion, The Railway Children and Kim all belong to a genre in which there is no magic, but a tremendous sense of what real children in adversity might achieve with courage, cleverness and luck.

Eleanor Updale�s Johnny Swanson belongs to this category, and it deserves the highest praise. Best-known for her charming Victorian adventures involving the burglar-turned gentleman spy Montmorency, she has taken an entirely new direction in a tale of a small, lonely boy who gets drawn into a serious crime involving the development of the TB vaccine. Johnny has lost his father in the First World War, and his mother barely scrapes a living as a cleaner for the local doctor in a small village. Picked-on as a �squirt�, he briefly befriends another ostracised child, Olwen, whose family are ill with tuberculosis. It�s 1929, and there is no cure: but Mrs Swanson�s employer Dr. Langford knows that in France they are developing what will become the BCG vaccine. How it gets to the wider public will, however, involve deception, incarceration, mystery and a murder.

Updale doesn�t put a foot wrong in this marvellous tale, but impatient readers should be warned that it had quite a long fuse. At first, you think you�re reading a story about a lonely child who develops a brilliant series of tricks by which to raise money. Johnny falls for an ad which promises to reveal the �Secret of Instant Height�, something he desperately wants. The answer, which costs him money he doesn�t have, is to �stand on a box.� You laugh, but also wince.

With a hundred small touches, the portraits of Johnny, his mother, the kindly Hutch for whom he has a paper round, their selfish neighbour Mrs Slack, Dr Langford and the venomous Miss Dangerfield are built up. His anxiety, his vulnerability and his status as a born victim make him not unlike Will in Goodnight Mr Tom � but Johnny is brighter, and readers will love him for it. He sees how he could play the same trick on other unsuspecting fools, and comes up with all kinds of ingenious cons, from selling an �official portrait of the king� (a stamp) to making your money go further (roll it down a hill.) These are more innocent times � and nastier ones, too, for when Mrs Swanson goes round to find out why she hasn�t been paid by the absent Dr. Langford, she is accused of murdering him.

From here, the story takes a darker, more gripping turn as Johnny sets about proving his mother�s innocence. The short, dialogue-filled chapters make the story race along. Updale�s sure sense of historical detail make Johnny Swanson an eye-opening read. 1929 is an time in which class divisions elicit unquestioning obedience, in which children trust adults and patients doctors far more than they should, so Johnny�s imagination and initiative are hidden assets.

Johnny Swanson would make a splendid TV drama, if any of the TV stations could wrest their budgets away from the tat currently on offer. Much as I enjoyed the Montmorency series, Johnny Swanson is of a different order, and it deserves to win prizes. Too often, modern authors use fantasy as an escape from the real evils that classic children�s literature confronts � much as adult literary fiction currently, and shamefully, uses history. This, at long last, is a corrective.�

Amanda Craig, The Times