Generally, when I read the word "radical," I reach for my TV remote. But Jansson's audacity is one that is entirely specific to her--it isn't showy or high-falutin', but clearly comes from her sense of who she is. Or, rather, was; she died in 2001, after a long career writing and illustrating a series of wonderful stories and comics for children. Most of the children's stuff is translated into English from Swedish, but only a couple of the adult books have been; the edition of The Summer Book we have is the current one, from NYRB, with an introduction by a hero of ours, Kathryn Davis.
The book, as Rhian mentioned in her post, is about a series of summers that a little girl spends on an island with her grandmother. The girl's mother has died--this is only mentioned once, but it suffuses every single scene in the book. The girl's father is living with them on the island, as well.
There is no plot--the novel is a series of vignettes. One of the three things that make me call this book "radical" is this particular tactic--though you've seen it before, it's rare to encounter a novel-in-stories that is so utterly confident in its abandonment of traditional narrative momentum. The second of the three is the book's treatment of time. The events, such as they are, clearly take place over several summers (many chapters start with something like "One summer..."), but they appear to be ordered by seasons: the early chapters take place in spring, the late ones August. Doesn't matter which year--what matters is the weather. The effect is to emphasize a certain habit of memory, the arrangement of experience by sensation. The third odd thing is the father: though he is living in close quarters with the grandmother and girl, and though he appears in almost every chapter, he never speaks. That is, he surely does speak, but his speech is never represented in the novel by dialogue. He's there, but this isn't his story, and his silent presence magnifies our sense of the mother's absence. I've never seen a writer do anything quite like this.
The book's climax--and yes, there is real emotional momentum here, subtly lashed to the changing seasons--comes when the girl, Sophia, dictates a book to her grandmother. The book, a description of the life habits of angleworms, is a devastating metaphor for the girl's separation from her mother; she gets the idea for writing it after a worm is accidentally cut in half with a shovel. "Presumably," Sophia dictates,
everything that happened to [the worms] after that only seemed like half as much, but this was also sort of a relief, and then, too, nothing they did was their fault any more, somehow. They just blamed each other. Or else they'd say that after a thing like that, you just weren't yourself any more.
It is a sad and beautiful flourish, and entirely original.
Jansson never calls attention to anything--she is perhaps the most self-assured novelist I've ever read. All you need to do is pay attention; and she is completely confident that you will. The prose is wonderfully simple, and ably translated by Thomas Teal; one gets the sense that Jansson is one of those rare writers who translate well.
Finally, I'd like to throw in a bit of praise for NYRB, which has reprinted a great number of fantastic forgotten classics--Stoner, Lolly Willowes, The Magic Pudding (another hilarious kids' book), and many others. I wish they would start publishing new books, by current writers. There is a need out there to discover and publish books that are liable to be forgotten before they're even published--quiet masterpieces with nowhere else to go.