The Winter Book UPDATE
Tove Jansson is best known (certainly outside her native Finland) for her Moomin books -- strange, melancholy stories shot through with longing for travel and longing for home. I owned and loved several of them as a child and they always made me feel enjoyably sad. I came to The Summer Book as an adult. It's a series of vignettes, set on a summer island, centred on the relationship between an old woman and her grandchild. It's beautiful and strange and wise, with the same enjoyable sadness and mood of nameless nostalgia and yearning as the Moomin stories.
A Winter Book is a selection of pieces from throughout Jansson's life, many taken from the memoir of her childhood, Sculptor's Daughter. I think I enjoyed these pieces the most, especially the story about the little girl who throws her torch onto an iceberg so it can drift away, lit with a greenish glow. A couple of chapters of letters sent and received were poignant and sometimes very funny.
But there were two stories that made me feel deeply anxious! One was set on a cruise ship (which I think was enough in the current climate to trigger unease). The other long story was called The Squirrel, and it was about a woman living alone on an island who develops an uneasy relationship with a squirrel who turns up there. I can't describe how anxiety-provoking I found this story. Perhaps the theme of solitude, the protagonist's attempts at self-discipline (she's a writer) and her eventual retreat into depression were just too close to the bone at the moment. Anyway.
The Moomin stories are often held up as simple, sweet, charming tales; you can buy loads of Moomin merchandise for kids. But there is a vein of darkness (Finnish noir?) in Jansson's work that surfaces quite plainly in this volume. If you're only after Moomin sweetness, don't look for it here.
UPDATE: By chance I just saw this article in The Guardian by Tom Holland about Mooninland Midwinter, which has both haunted and comforted him since childhood, and which he finds particularly pertinent in this time of lockdown -- Moomintroll wakes up in the midst of hibernation and finds his world changed and cold and frightening. I don't remember reading this one as a child but it does sound scary in the same way that A Winter Book is sometimes scary.