I am pretty sure it was one of you lovely readers who recommended The Tortoise and the Hare by Elizabeth Jenkins. Unfortunately, I can't remember who, but thank you for the recommendation.
At first glance, The Tortoise and the Hare checks off all the boxes: British, mid-century, domestic, upper-middle class. That said, it is too dark to be considered a cozy book, but I loved it all the same and have marked it for potential re-read and I'll definitely be looking up more books by Elizabeth Jenkins.
It is the period shortly after World War II, and Evelyn and Imogen Gresham have been married for eleven years. (For the first few chapters, I had to keep reminding myself, "Evelyn is a man's name.") Evelyn is in his early fifties, a successful and important barrister. He's one of those men who is always in command; unfailingly sure of himself and very handsome. Imogen, age 37, is gentle and beautiful, arty, romantic, and perhaps somewhat impractical. They have an 11 year old son, Gavin, and live in an idyllic riverside house in Berkshire, far enough away from London that Evelyn needs to sleep in a flat they keep there when he is working.
From the very beginning, you can see that Imogen is unable to assert herself in front of her husband. He knows best, and she is silly, vague, and impractical. It's also clear that Evelyn doesn't respect Imogen, and as a result, neither does their son.
Enter Blanche Silcox, a neighbor, fiftyish, stout, and frumpy. Blanche is also rich and eminently capable, the opposite of Imogen. Evelyn and Blanche talk on the phone every day and Blanche is always on hand to drive him back and forth to London. It's clear to the reader that something untoward is happening, but it doesn't occur to Imogen that an unattractive woman like Blanche could possibly threaten her marriage.
As much as I enjoyed this novel, I found it uncomfortable to read because Evelyn is an abusive husband. Politely abusive, but abusive nonetheless. There's nothing physical, no shouting, but a few well-chosen words here and there keep Imogen thoroughly cowed. For example, towards the end, when Imogen has realized that Evelyn and Blanche are actually lovers, she naturally becomes more withdrawn. Evelyn turns this against her, saying things like, "Since you obviously don't want my company, I'll have lunch with Blanche." It's a masterful portrayal of emotional manipulation, but it made me sad.
Imogen rehearses everything she says or does, so as not to irritate Evelyn and she goes out of her way to attend to his comfort, although to no avail, since he finds all his comfort from Blanche. She's so terrified of his reactions that she can't even bring herself to call him when their son gets into serious trouble at his boarding school.
Blanche, meanwhile, is just as horrid as you'd expect: bossy and heavy handed. Naturally she takes a hard line against those less privileged than she, arguing vociferously that the new National Health Service is only going to encourage malingering among the lower orders. She has no taste either.
In the end, Imogen seems to be heading for a very dark place, but help arrives from an unexpected source. It's possible that two broken people might be able to heal each other.