A letter from Tove Jansson to her life partner, the artist Tuulikki Pietilä.

Written toward the end of Jansson’s life, “Once, at a park,” starts out as a classic piece on writer’s block—but there is much more going on.

Written toward the end of Jansson’s life, “Once, at a park,” starts out as a classic piece on writer’s block—but there is much more going on.

Translated into English for the first time here, Tove Jansson’s “The Island” is at once a short story, an essay, and a prose poem. It reads like a sketch for her novel ‘The Summer Book.’