Koster is a sharp and intense novel about truth, literature, and botany—and not least, a love letter to the Bohuslän summer.

Oda Bakken loses her job as an advertising copywriter and is contacted by a former client with a proposition: she is to write a biography of Lina Ebbel, a multi-millionaire and the founder of the natural cosmetics brand "Linné AS." Oda travels to the island of Koster, where the elderly woman lives. But the writing assignment proves far more difficult than first anticipated, as her subject has a highly unconventional relationship with reality.

The Swedish archipelago idyll of Koster frames the story with its perfect Swedish summer. But as the holidaymakers head home, the restaurants close, and the sea turns white, an unsettling underworld of unexplained phenomena, human experimentation, and jealous husbands begins to creep in.