Summer 1951. The Löwander family is preparing to open a summer restaurant on Gällnö in the Stockholm archipelago. There, Nina meets Calle again for the first time since she tried to take her own life.

Peter and the staff prepare the midsummer celebration at the summer restaurant. Chef Backe has high hopes for the evening. Nina and Calle are colleagues but, beneath the surface, deeper feelings burn.

Nina travels down to see Erik and Christina in Skåne, but it will not be the harmonious reunion she hoped for. Helga suspects that something happened between Nina and Calle on Midsummer's Eve.

As the restaurant's seasonal closing is approaching, Calle and Sonja's marriage is cracking at the seams. In Skåne, Nina sinks deeper into depression, while Helga and Backe try to help her.