To the reviewer's jaded palate, stories set in invented other worlds, involving magical apprenticeships and witchcraft contests, are scarcely more welcome than yesterday's cold fillet of a fenny snake, so it is a pleasant surprise to come across a really enjoyable example, one that avoids portentous moralizing or mythologizing in favour of a rapid and remarkably sustained comic action. Diana Wynne Jones's Charmed Life, in spite of touches of Joan Aiken and, in the final chapters, C. S. Lewis, is an outstandingly inventive and entertaining novel, which never for a moment loses its characteristic pace and verve. Its setting is a world whose culture has evolved through magic rather than technology, where taxpayers subsidize research into spells and warlocks appeal to their MPs when deprived of their powers. There are some splendid set pieces of witchery, such as the havoc caused during a dull sermon when the sober...