The Swamp of Death, by Rebecca Gowers

Part of the grim power of murder, real or fictional, is the ability to shine a harsh light on its context. It is the crime that reveals the most about us, and the world we live in. In The Swamp of Death, Rebecca Gowers has disinterred a real-life case as characteristic of its time and place as a story featuring Sherlock Holmes or Hammett's Continental Op.

Early in 1890, Douglas Pelly, the son of a clergyman, set sail for Canada, where he hoped to make an agreeable living as a gentleman farmer. He had invested his small fortune in the farm of his reassuringly well-bred companion, Reginald Birchall. Birchall's pretty wife travelled with them. Pelly was disconcerted to find an unexpected fourth in the party. Frederick Benwell, son of a half-pay colonel, was also hoping to become a farmer.

Gradually, Pelly's suspicions were aroused. Birchall told lies and fostered distrust between Benwell and Pelly. Benwell's skin was unusually dark because he had an Indian grandmother, which Pelly later found sinister. Mrs Birchall was ladylike but sometimes the worse for drink.

The travellers made their way by train to the Canadian border. By now, it was obvious that the farm business, if it existed, was nowhere near as prosperous as Pelly had been led to believe. At one point, Pelly was convinced that Birchall planned to kill him. But it was Benwell who died.

Birchall took him into Canada and left him there. A few days later, a body was found in a swamp: frozen solid, with two bullets in the head. After defrosting, the corpse was identified as Benwell's, and Birchall was charged with murder.

Birchall was a conman who lied fluently from start to finish. But his charm, his gentlemanly bearing and his fortitude won many friends. John Murray, the detective who put together most of the case against Birchall, was a far less attractive personality, and just as capable of lying.

The author is Pelly's great-granddaughter. Drawing mainly on press reports and Pelly's accounts, she teases a fascinating story from the tangle of contradictory material concerning the drawn-out investigation, the conflicting jurisdictions, the trial and the brutally-bungled execution of Birchall.

The circumstances of Benwell's death remain mysterious. The evidence against Birchall would not have convicted him today. The case remains fascinating partly because more than a man was on trial - this is a story about class, about race, about the failure of justice, about Canada's uneasy relationship with its mother country, about a world growing smaller with the telegraph and telephone, and about the tendency to assume if someone is guilty of something, he is therefore guilty of everything. It leaves you with the feeling that the wrong person was on trial: perhaps the detective should have been in the dock.

The reviewer's latest novel is 'The American Boy' (HarperPerennial)