Finn lives with his mother in a working-class suburb of Oslo. It is 1961, before oil, before anyone had any money at all. One day a mysterious half-sister appears, turning their lives upside down - why is she so different from every other child?

When his mother takes a lodge, Finn is enthralled by the bad language and Bakelite T.V. he brings with him, but the newcomer has his own plans for the family. And throughout the long summer, Finn cannot help feeling his mother is keeping a powerful secret from him, pushing them further and further apart.