Martin Beck, Gunvald Larsson and Alice Levander investigate the mysterious murder of an accountant that was found shot to death at the airport parking. At the same time a reporter receives a package from an anonymous source, with information regarding the embezzling of funds that should have been used for fixing up nuclear reactors. When the reporter contacts Beck, his home gets blown up by a bomb.

Singel mother, Elin, experiences her worst nightmare when her son dies in a drowning accident. She tries to get her life back on track after the tragedy together with her daughter Storm (10), but there are rumours around school that somebody saw Storm push her brother in the river on purpose.

Benjamin's insecurities bubble to the surface when his girlfriend Maya recounts a past sexual escapade in Brazil — and a quarter-life crisis ensues. Bird Hearts cleverly dissects Nordic liberalism and the fragility of the male ego.