The book follows the titular Moomin family as they arrive on a deserted island in the middle of the sea, documenting their experiences as they become familiar with their newfound surroundings. The book is notable for its introspective and contemplative tone, which is in contrast to the other books found within the Moomin series.
The book is based primarily around the character of Moominpappa, who was heavily inspired by Jansson's father, Viktor Jansson.
The book's original title is a loose reference to Ernest Hemingway novel The Old …