The Twilight Hour, by Elizabeth Wilson

Elizabeth Wilson's third crime novel is a book to read during the heatwave to keep you cool. The observant writing ensures that the iciness of the winter of 1947 - with fuel-starved Londoners in rationed clothes scavenging for firewood on bombsites, and 20-watt bulbs dangling near broken windows in draughty stairwells - rises off the page to nip your fingers.

At 20, Dinah Wentworth is newly married and no longer needed in her secretarial job at the War Office. She hangs around Fitzrovia pubs with her husband Alan, drinking cherry brandies while he looks for backers for his films among the spivs and speculators, the artists and the cold, doctrinaire communists. When one of the communists is arrested for a murder that Dinah knows he cannot have committed - for reasons that she cannot tell Alan, or the police - she sets out to find the truth.

Her quest takes her into a world of surrealist painting, property speculation, austerity éclairs and middle-class men. These come as a bit of a surprise. Back in her posh boarding school, she had understood that all men were either "public school and Oxbridge" or "a docker or a miner or something like that". The urgency of the murder enquiry is underlined by the likelihood that the accused will, if convicted, be hanged.

Capital punishment can usually be relied upon to add an extra frisson to a whodunit. Here, Dinah, whose observations elsewhere are sharp and individual and whose fashion notes as vivid and fascinating as you would expect from a Wilson heroine, whether describing a film star in her "close-fitting black dress with coffee piping" or a communist zealot's belted tweed, green beret and ringlets, lapses too often into generalities. The "pornographic pleasure" of press coverage of executions is summed up in a list of journalistic clichés, with little sense of how different it feels to read that sort of thing about someone you know.

And the letter from the condemned man to his friends comes across as little more than an authorial device to establish back-story. When matters are finally resolved, Dinah's husband makes a speech that announces, "I'll always think of him as my friend." Since this has never been in doubt, it's an oddly pedestrian ending to an otherwise exciting, quirky story and a gripping evocation of an icy time.

The writer's novels include 'Other Names' (Penguin)