When psychology student Marcus Nielsen is found dead, everything points to suicide. But when Detective Inspector Thomas Andreasson and his colleague Mia Holmgren investigate the case, they begin to suspect that it is murder.
Thomas and Mia continue the investigation into Marcus’ death and discover that he had arranged several meetings with former commandos to talk about group psychology. When another commando is found murdered, they realise that the perpetrator is targeting those who graduated in the 1980s.
Thomas and Mia try to track down all the commandos who were mixed up, either directly or indirectly, with Marcus’ murder. Meanwhile, they learn that Commander Cronwall has disappeared and it turns out that he lied in that he had in fact met Marcus.