In 1944, a Scotswoman named Helen Duncan was tried at London's Central Criminal Court, on charges under the Witchcraft Act of 1735. No one supposed that "Hellish Nell"—as she'd been known in her childhood—flew about on a broomstick wearing a pointy hat. Her business was that of a high-earning, grossly fraudulent spiritualist medium.

According to historian Malcolm Gaskill, whose dispassionate but involving Hellish Nell: The Last Witch in Britain (Fourth Estate, 402 pp.) tells the story of Helen Duncan, the archaic legislation was employed because it gave the best guarantee of her conviction. The eight-day trial—held in a blacked-out city reeling from bombing raids—caused a sensation in the popular press, which called Nell Duncan "the Saint Joan of Spiritualism." The distress and uncertainty of war time had given fresh impetus to the spirit game, but frauds were usually dealt with in the lower courts under laws designed to trap traveling fortunetellers. It was natural that Helen Duncan attracted public sympathy. She was an uneducated woman, well into middle age, and chronically ill. Why, people asked, did the government think it vital to silence her by a prison sentence?

The answer, according to her friends and conspiracy theorists everywhere, lay in a seance that Nell had given in the naval base of Portsmouth, three years earlier. A young sailor had materialized, claiming to be from HMS Barham, a warship stationed in the eastern Mediterranean. His anxious relatives contacted the naval authorities, and gave those authorities a big problem: They alone knew that the Barham had been sunk, with the loss of more than 850 lives, but for strategic reasons the government was concealing it from the public and would not officially announce it for some three months.

How did Nell find out that the crew of the Barham were dead? Inside information seemed an unlikely source; so did she really have the psychic powers she claimed? In any event, the security services were involved in building the case that put her behind bars.

Gaskill has taken apart the case of Hellish Nell, exploring not just this central incident but also her early life, her career history, and her motivation, in a narrative which has much to tell us about the way that poverty and war impact on the human imagination. In the end, it is impossible not to feel sorry for the old fraud--while wondering why the established religions failed so badly that the terrified and the bereaved sought comfort from revenants made of butter muslin and chewed paper.

The Adversary by Emmanuel Carrere (translated by Linda Coverdale, Metropolitan, 191 pp.) is one of the strangest, strongest books I have read in years; it demands to be consumed at one sitting, such is its intense and bitter flavor. It is an exploration of a false identity, and a true crime: in 1993, Jean Claude Romand killed his wife, his children, and his dog, then drove across country to murder his elderly parents. As far as his friends and neighbors were concerned, Jean Claude was a doctor who commuted across the Swiss border every day to his senior post with the World Health Organization in Geneva. In the wake of his crime, it turned out that WHO had never heard of him.

For eighteen years he had sheltered under a false identity. A small lie, told to cover himself when he was a student, had brought him to spin an all-encompassing web of deceit. Emmanuel Carrere visited him when he was in prison, and tried to tease out the secrets of his peculiar psychology. His short and tightly written book is piquant, very French: shocking, exact, and wise.

Bad Blood by Lorna Sage (Morrow; available in the United Kingdom from Fourth Estate; 281 pp.) is an exquisite memoir, and last year's winner of the Whitbread Prize for Biography. Lorna Sage was a literary critic, and head of the department of American Studies at the University of East Anglia; she was a critic and teacher who nurtured and empowered other writers.

She was also, it proved, the survivor of an extraordinary and tumultuous childhood, which she recreated in beautiful, witty, and considered prose. She died, at fifty-seven, a week after receiving the Whitbread award, leaving us a classic fragment of autobiography which has been compared to Edmund Gosse's Father and Son. Her photograph, as a radiant teenage blonde, is on the book jacket; but it's the exquisite writing between the covers that really lights up her life. This is the book I am buying for my friends, knowing that it will amuse them, awe them, and touch their hearts. When I teach writing, I say it and say it again: To write a great book, you don't have to sail the seven seas, commit great crimes, dramatize, or even invent. The extraordinary is apt to be ephemeral. It's in ordinary lives, lived bravely, that we see most clearly the transfiguring, persistent, universalizing power of art.

Related: Lucy Lethbridge reviews Hilary Mantel's novel Wolf Hall.