Winter in the zoo, and Ackroyd, the tiger who loved his keeper so much that he started by licking him and ended up eating him, goes to church with other escapees to celebrate Christmas.

Grouped at the back, their pelts smelling "like fierce incense", the animals sing angelically; they are invisible to the rest of the congregation with one exception: a small boy "thought to be retarded". Treading a narrow path between fable and fantasy, Gardam brings her story through to a satisfying end.

Subtitled "Hauntings and Grotesques", the book begins with five cautiously optimistic anecdotes in the spirit of Thomas Hardy's poem, "The Oxen". Two rival lawyers, widowers, retired from practice in Hong Kong to adjacent cottages in Wiltshire, explore the possibility of friendship in the cold season, "hoping it might be so". "Miss Mistletoe" is tolerated once a year at the well-heeled Infills, where she sits with her face "in its permanent rictus grin, giving the impression of a delighted grasshopper in a paper hat." Put off one December, she returns the next with a baby. The chilly hospitality of her hosts certainly gets its comeuppance, but at the expense of the story: no amount of authorial approval can make Miss Mistletoe's sudden fecundity convincing.

There are similar weaknesses in "The Pillow Goose", aspiring to fairy tale, and "Light". It's an easy step down from magic to whimsy and, in Gardam's case, it threatens to happen whenever her novelist's sure sense of plot is subsumed by an urge to point a moral.

Two ghost stories round the dozen and see the writer back on her quirky track. "Soul Mates" was commissioned by the BBC, and must have made atmospheric radio. The voices of a slightly querulous quartet soon establish themselves; meeting on holiday, facing retirement, Francis and Patricia, Jocelyn and Evelyn discover they are uncannily alike. One couple invites the other to make a visit on their way home and what happens next is weird, frightening; all too credibly haunting, in fact.

The Green Man of the final story is something of a test case for anyone writing about the supernatural. Prefaced by a line from Ronald Blythet - "the Green Man is no enemy of Christ" - and set in East Anglia, Jane Gardam's evocation of the legend stands up well. Her Green Man can be mistaken for a tree stump in winter and a scarecrow in spring, but when summer comes he strides about his kingdom. He sits on the moon debating with the devil; then returns to the community where he is sometimes shunned, like Peter Grimes, sometimes honoured. He's a wonderful creation.