In winter, terrible storms batter the Baltic island of Hammersö, the setting for Linn Ullmann’s fourth novel. In summer it’s an idyllic holiday retreat where families like the Lovenstads return year after year, lured by its safe, small-community feel and the strange quality of the light on the water. It’s a place to store up wonderful childhood memories, one might think – but for Erika, Laura and Molly, the now grown-up daughters of Isak Lovenstad, the past throws troubling shadows.

Just for starters, Hammersö is where the half-sisters are first shocked into awareness of one another’s existence. Isak, a pioneering obstetrician, is a charismatic womaniser, divorced from his first wife (Erika’s mother), devoted to his second, Rosa (who was Laura’s), yet unable to resist the extra-marital fling that produced Molly.