The body of a young woman is found carved up and buried in a forest glade in an innocuous Stockholm suburb. As Fredrika Bergman and her colleagues in the Stockholm Police continue to excavate the site, several more bodies are unearthed.

Meanwhile, the name of a children's fiction author keeps cropping up in the investigation. All the bodies in the mass grave appear to have some connection to the old author and her enigmatic circle of friends - The Guardian Angels - who formed an elitist film club in the 60s. But the elderly writer is mute and incapable of helping Fredrika with the investigation.

But the complex case starts causing rifts within Alex Recht's team and new revelations cause them to enter morally ambiguous territory. Now under investigation by Internal Affairs, the unit approach the case's resolution with a sense of impending doom. The author has kept a dark secret under wraps for decades, but now that the truth is seeping out only one question remains: which will be the next body to turn up in the grave when the killer returns to the forest?