Anders Danielsen Lie and young newcomer Emily Matthews also star in this adaptation of Tove Jansson’s novel about a grieving family on an islet in the Gulf of Finland.

A lovely intergenerational moment toward the end of Charlie McDowell’s The Summer Book captures the restorative magic of its atmospheric setting on a tiny island in the Gulf of Finland.

Adapted by Robert Jones from the novel by Tove Jansson — the beloved Finnish writer and illustrator of the enduringly popular Moomin books and comic strips — McDowell’s screen version remains true to the source material by sharing its attention equally between its characters and the elemental forces surrounding them. You can feel the brisk chill of Baltic Sea waters lapping at the shore; the soft caress of sunshine in a place where it’s always sweater weather; the violence of a storm that whips up without warning.

While the book is fiction, it’s drawn from Jansson’s many summers spent on the rocky, outer-archipelago islet of Klovharu with her niece, in a modest cottage the author built with her brother in 1964. Jansson, whose early life was depicted in the 2020 Finnish biographical drama Tove, spent five months a year for three decades on the island with her life partner, who shot the 8mm home movies seen in an epilogue in that film and on the end credits here.

The deep roots of the writer’s emotional and physical connection to the place provide a foundation for the slender story. Those qualities are fully manifested in Close’s finely etched characterization. The unnamed grandmother is a hardy woman quite content to live with minimal comforts in an unheated, rustic house even as her health declines. She passes on that love of the island — its rocks and mosses and patches of pine forest — to her granddaughter Sophia (bright newcomer Emily Matthews) in intimate exchanges throughout.

The two of them have come to the remote island with Sophia’s taciturn father (Anders Danielsen Lie) in the wake of a staggering loss that is left unspoken for much of the film. But, starting with the desolate look on his face as he picks up a sunhat left behind the previous summer, it becomes clear that the death of his wife has caused him to shut himself off, retreating into his work as an illustrator. Sophia interprets her father’s silence as a lack of love for her since her mother died, and her grandmother intercedes as a mediator only in the most discreet ways.

Only once does she speak sharply to Sophia’s father, when he bitterly comments on a boatman’s reluctance to come to the house while delivering fireworks for the Midsummer celebration: “The stink of grief keeps him away.” “Or self-pity,” responds his mother.

That feeling seems entirely foreign to her. When Sophia asks, with the bluntness of the young, when her grandmother is going to die, she replies, “Never you mind. Soon.” Her serene acceptance of that inevitability even extends to her kicking off the covers in bed at night and folding her hands across her chest, seemingly more curious than fearful of what the inside of a coffin might feel like.

The grandmother’s creeping infirmity does little to curb her excursions with Sophia. They go by boat to a neighboring island, where newcomers have built a large, modern home that sits intrusively in the otherwise unspoiled landscape. The old woman’s amusing disapproval is barely softened even when the owners turn out to be genuinely friendly.