The Day He Died by "Lewis Padgett" (Henry Kuttner and C. l. Moore) (1947)
The Kuttners' second mystery novel avoids the humor of the previous The Brass Ring (aka Murder in Brass) and carries a much darker tone, reading like a more psychological Cornell Woolrich thriller.
Caroline Hale writes mystery stories for the pulp magazines. He uncle and only living relative is Jonas Bruno, an exporer who writes best-selling accounts of his exotic travels. Three years after the end of her eigth-month marriage to the violent Ray Kerry, Caroline thought she was getting her life back, but a number of unexplained things in her life begin to shake her confidence.
She's been getting tired and groggy. Things go missing our suddenly appear in apartment, her dreams have become vivid and disturbing and she wonders if they are really dreams, she begins to see things...hallucinations. Worse, a story she submitted was found to have a dialogue lifted directly from Oscar Wilde's A Woman of No Importance after its publication. Five time since then she has found passages in her manuscripts that have been copied from well-known works. Caroline has no memory of plagerizing these works but no one but her could have written them; her apartment was securely locked and chained, she put thread across her doorways and poured flour on the floor of her apartment in hopes in an atttempt to discover who ws doing this. The results proved that no one else could have done it, that she herself was acting unconsiously.
At the same, her former husband showed up, wanting to come back to her, Ray had been living for the past few years with a medium who, at times, did not have to fake her spiritual connections. Now Ray, who never had any money, appears flush. Caroline fears that Ray is stalking her, but now nobody knows where Ray is and a lot of people want to find him -- people who think Caroline can lead them to her ex-husband.
With Caroline's world spinning out of control, she is present when someone slashes the throat of a washed-up reporter. A body is found buried in her uncle's cellar. $40,000 in drug money is missing and a crime syndicate wanrs it back. Connecting all three events is Caroline, who fears she is being watched and in danger. The stress leaves her in and out of a fugue state.
The reader feels (and hopes) that Caroline is being gaslighted, but there is this doubt that she is not, that her delicate mental balance is tipping the scales toward madness. The authors have weaved a suspenseful thriller with strong psychological overtones.
A good read. Recommended.