I have been reading my way through all of Muriel Spark, finding that there is enormous variation between the ones I like and the ones that make me raise an eyebrow and go, "errr...?"
This is one of the latter, a very strange book, which is reminiscent to me of one of the darkest Ealing comedies. A granny who smuggle diamonds in bread (yes, I did keep thinking of Alec Guiness in drag), an assortment of odd people, and most of all the weird Caroline Rose who keeps hearing voices which indicate she knows the novel is being written about her.
At this point, we are suddenly into fiercely post-modern, self-aware, Italo Calvino territory. You may really enjoy it, I found it off-puttingly strange. And I do enjoy a lot of post-modern fiction, but this is such a weird mix of that and a rather English comic novel. Anyway, she was clearly defiantly trying to do something new, from her very first publication, and that I really admire. Even when you are not enjoying her books, there is that strength and intelligence in them which you cannot help but revere.