I've been saving this one for a metaphorical rainy day, it was worth the wait. Greyladies books aren't cheap so there's a certain amount of pressure to get the choice right. I'm not entirely sure of who Susan Pleydell was, I know that roughly speaking Greyladies specialise in the adult titles of people better known for children's books but that doesn't leave me much wiser. The brief biographical details tell me Susan Pleydell was a non de plume, that she was born in 1907, which means that by the time this book was published in 1960 she would have been much the same age as the McKechnie parents, grew up in Scotland, and that she was well educated, musical, worked as a teacher, and married a headmaster.
The Glenvarroch Gathering comes together after the McKechnie family decide that paying guests might be just what they need to make ends meet a little more easily in their Scottish house. Glenvarroch is large enough to easily accommodate an extra 7 people on top of a family of 5 (despite only having 2 bathrooms) and the McKechnie's can keep a cook. Everything is shabby but nothing is actually falling down. It sounds like a comfortable enough way to live, but with the definite impression that a bit more money would be useful to maintain that comfort.
There is naturally a crime to spice things up, but what makes for a splendid change is that it's not a murder. Someone is on the run with £50,000 in stolen diamonds, and whilst they're dangerous they don't want to be the one who gets their hands dirty with actual violence if it can be helped. What it really is, is a book about class, attitudes, and owing of age.
The McKechnie's are solid upper middle class people, educated, intelligent, hard working (Mr McKechnie is a professor, the children will need careers). There is a sense that the older generation is well aware of its relative privilege as well as the cost of maintaining it. For the younger generation it's still a question of things taken for granted - both the luxuries of staff, a secure background, space, and the freedom to enjoy it, as well as the relative discomfort of a shabby house with a limited number of bathrooms and a general air of make do and mend. (I know it sounds like I'm obsessed with the bathroom arrangements, and maybe I am, but it's one of those markers between modern convenience and old fashioned inconvenience and reminds me very much if childhood.)
The family can easily accommodate it's American and academic guests albeit with something if a boarding house atmosphere. They are types they can understand with similar values, and the guests can accommodate them, fully understanding that this way of life is something of a survivals of be enjoyed until they return to reality. The Anthony's are something else. Their glamour is dazzling, fun at first and then increasingly disturbing. They change the dynamics of the party, upset old friendships, and generally start to make things uncomfortable. They are of course not the right sort.
It works because Pleydell obviously knows young people and does a very good job capturing some part of the confusion of growing up, and a very good job on capturing the amused tolerance of their parents as well as their occasional anxiety for their offspring. She makes the countryside come alive too, as well as the charm of shabby country houses. The crime element adds enough tension to make it a real page turner, with the climax holding genuine threat - posed as much by the weather and the landscape as by any human skulduggery, and again I really like that. A good murder mystery is fun, but it's not the only crime and this book makes me yearn for more with a close to zero body count.