Before she started writing psychological thrillers as Barbara Vine, Ruth Rendell made regular detours into that sub-genre. To Fear a Painted Devil is one of her earliest non-Wexford novels, and while interesting, the psychology doesn't stand up to the passage of 50 years. Patrick and Tasmin Selby are replacement gentry - wealthy, aloof, married first cousins (as normal as that seemed to Jane Austen's characters, I'm assuming it was unusual by the 1960s) - who appear to have the perfect life. They don't of course. Patrick is remote, distant, and psychologically abusive; Tasmin was raised to be dependent and there are no other suitable and suitably rich men for her to marry, even if she could get a divorce.
The neighbors, of course, don't know the state of the Selbys' marriage when they assemble for Patrick's birthday. It's an awkward grouping, including impoverished old money, social climbers, harried parents, Patrick's mistress, a middle-aged man and his much younger third wife, and the local doctor. Just the ordinary social gathering in this newly built bedroom community, until Patrick and a late-invited guest try to eliminate a wasps' nest. They end up disturbing the nest and the wasps sting Patrick several times, but Dr. Greenleaf treats his stings with an antihistamine and a sleeping pill. When Patrick dies in the night, Dr. Greenleaf assumes he either took an extra sleeping pill or had an unknown heart condition. That's not the case - he's been murdered, and Dr. Greenleaf solves the mystery (but not too easily). I did as well, but I was somewhat hampered by the setting. Mid-20th Century England is a bit of an uncanny valley for a modern American. It's recognizable, but foreign enough that I can't really trust my perceptions. That's only a problem when reading a mediocre book, and it didn't bother me while reading To Fear a Painted Devil.